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Last Updated: Friday, February 3, 2012 11:30 AM
Chapter 6 - Historical Archaeological Resources: Evaluation and Treatment
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- 6-1 Introduction
- 6-2 Professional Qualifications
- 6-3 Gathering Information
- 6-4 Evaluation of Historical archaeological Resources.
- 6-5 Letter Reports for Resources That are Not Eligible
- 6-6 Test Excavations
- 6-7 Excavation Proposals
- 6-8 Pre-Field Preparation and Fieldwork
- 6-9 Laboratory Analysis
- 6-10 The Historical Resources Evaluation Report..
- 6-10.1 Determinations of Eligibility
- 6-10.2 Historical Resources Evaluation Reports Without Excavation
- 6-10.3 Jointly Prepared HRERS
- 6-10.4 Historical Resources Evaluation Report Review and Distribution
- 6-11 Environmentally Sensitive Areas
- 6-12 Data Recovery Plans, and Treatment Plans
- 6-13 Coordinating Consultant Studies
- 6-14 Construction Monitoring and Post-Review Discoveries.
- 6-15 Historical Archaeological Study Permits
- 6-16 Peer Review and Approval of Historical Archaeological Documents
- 6-17 Endnote
This chapter presents Caltrans' policies and procedures for evaluating and treating historical archaeological resources, including sites and districts composed of historical archaeological sites. In California, the historic era generally is defined as the period following initial Euro-American exploration in the region and establishment of the first Spanish mission in 1769. Sites, as used in this chapter, specifically encompass both historical archaeological sites and those places identified as Traditional Cultural Properties (TCPs). These procedures have been developed to comply with Section 106 of the National Historic Preservation Act of 1966, as amended, and the provisions of the Section 106 Programmatic Agreement (Section 106 PA). The same general process is also used for compliance with the California Environmental Quality Act (CEQA).
Throughout this chapter the term “historical archaeologist” means Caltrans staff who are certified as Principal Investigators - Historical Archaeology under the Professionally Qualified Staff (Caltrans PQS) requirements of the Section 106 PA and consultants who meet the same qualifications (see Section 106 PA Attachment 1).
For federally assisted state and local projects, as well as state-only projects, there are two types of reports that are used to document historical archaeological resources:
1) The Letter Report is to be used only when the provisions of the Section 106 PA do not apply, such as for projects involving tribal land or state-only funds. It is used to document cultural resources that have no potential for meeting the eligibility criteria for inclusion in the National Register of Historic Places (see Section 6-5 and Exhibit 6.1). The Letter Report is attached to the project’s Historic Property Report (HPSR), or for state-only projects, the Historical Resources Compliance Report (HRCR).
2) The Historical Resources Evaluation Report (HRER) is used to document evaluations of all types of historical archaeological resources. Section 6-10 and Exhibit 6.2 contain detailed instructions for completing an HRER. Caltrans sends the HRER to SHPO as an attachment to the HPSR Section 106 consultation package (see Chapter 2 for guidance on preparing an HPSR and SHPO consultation). For state-only projects, the HRER is attached to the HRCR.
When archaeological excavation is required to identify or evaluate a site, the historical archaeologist prepares a proposal for an Extended Phase I (XPI) or a Phase II excavation (See Exhibits 5.2 and 5.4). Prior to implementation, a historical archaeologist who is qualified at the Principal Investigator level peer reviews the document (peer review procedures are discussed more fully below and in Section 6-16). The XPI and Phase II proposals are in-house documents used to guide Caltrans activities. The historical archaeologist reports the results of excavation and, if appropriate, site evaluation, in the HRER. Caltrans uses other report formats to plan for data recovery or post-review discoveries and to report the results of data recovery (Phase III) studies.
This chapter builds on the guidance contained in Chapter 5 on general archaeological studies. It begins by discussing the qualifications needed to evaluate different types of historical archaeological resources. Subsequent sections then discuss the evaluation process for historical archaeological resources that do not require excavation, the evaluation process for historical archaeological resources requiring excavation, the preparation of HRERs, treatment procedures necessary to complete the Section 106 process, and compliance procedures for state-only projects.
Qualifications required for evaluation and treatment of historical archaeological properties are dependent on the nature of the resources present. Multi-disciplinary teams may be necessary. See Chapter 1 Section 1-3.4 and Section 106 PA Attachment 1 for a discussion of minimum standards and guidelines, as well as certification levels under the Section 106 PA. Under the Section 106 PA, staff must meet the minimum qualification levels for Co-Principal Investigator (Co-PI) or Principal Investigator (PI) to evaluate historical archaeological sites. Exhibit 1.5 Table 1 describes the PQS levels required to perform archaeological activities and Table 2 describes PQS levels to complete the accompanying studies and construction monitoring. Those not fully qualified as historical archaeological Principal Investigators (PI) may perform many tasks with under direct supervision of historical archaeologists qualified at the PI level. Note that a Caltrans PQS at the PI level for historical archeology must peer review all historical archaeological work completed under the terms of the Section 106 PA.
Certification as a Caltrans PQS for PI historical archaeologist is generally required to assume lead responsibility for evaluating historical archaeological sites. PI-level prehistoric archaeologists may also evaluate historic-era Native American archaeological sites. Co-PI-level historical archaeologists, under the direction of a PI-level historical archaeologist, may evaluate historical archaeological sites that do not require excavation (See Exhibit 1.5 Table 1).
Caltrans PQS in architectural history and consultants meeting the same qualifications (see Section 106 PA Attachment 1) often are trained in historical research, may provide valuable assistance with background research for evaluations of historic-era archaeological sites, and may need to be consulted prior to evaluating these resources. An interdisciplinary team including qualified architectural historians and historical archaeologists collaboratively should evaluate resources with both built and historical archaeological elements, as well as other types of cultural resources such as ruins of buildings and structures, cultural landscapes, battlefields, cemeteries, and the locations of important events. In addition, professionals with knowledge of cultural geography, the history of technology, folklore, and social history, to name a few, also may add valuable insights to understanding material culture. Sometimes this expertise is best obtained via consultant contract. . See Chapter 4 Section 4-4.2 and discussion of specific resources in Chapter 7, particularly Sections 7-4 and 7-8.5. Teams may be created from a combination of District Caltrans PQS, Headquarters PQS, or appropriately qualified consultants. Send requests for assistance from Headquarters staff to the Chief of the Cultural and Community Studies Office (CCSO).
The amount and types of information needed to complete the evaluation of a historical archaeological site will depend on the type of resource, its integrity, and the quality of available information about it. Caltrans PQS will determine when to contact the appropriate Information Center for a records search and will specify the level of information needed. Local agencies should be advised not to order record searches unless Caltrans PQS determine it necessary.
Historical archaeological resources that meet the criteria for “Properties Exempt from Evaluation” in Section 106 PA Attachment 4 clearly have no potential to be eligible for the National Register of Historic Places (National Register) and need not be evaluated. Only appropriately qualified Caltrans PQS or similarly qualified consultants may exempt such properties, as outlined in Attachment 4. The information gathered during the identification phase may sometimes be sufficient to make such summary conclusions without further research. Exhibit 4.1 contains guidance on sources of information. [In special circumstances, such as on tribal lands where the Section 106 PA does not apply but there are resources that meet the criteria for exempt properties as outlined in Section 106 PA Attachment 4, appropriately qualified Caltrans PQS or consultants may address such properties in a Letter Report. Section 6-5 and Exhibit 6.1 contain guidance on using Letter Reports.] All other historical archaeological resource evaluations should be documented in an HRER (see Section 6-10).
Information gathered as a result of identification activities such as background research, reconnaissance survey, and archaeological survey will usually need to be supplemented with additional research in order to complete evaluations of all but the most compromised resources. Additional historical research, interviews with knowledgeable individuals, or limited archaeological excavation, depending on the nature and complexity of the resource and the quality of available historical information, also may be necessary. Because of the expense and time involved in archaeological excavations, testing is normally undertaken only when there is a clear potential that the work will yield important information.
Historical research (which should encompass a review of the relevant literature as well as property-specific research, including interviews) always precedes excavation because it provides the justification for any necessary excavation program.
The nature of the resource, amount and quality of available documentary information, and current research issues will determine whether archaeological excavation may be appropriate and necessary. When archaeological excavation is conducted to determine site boundaries (e.g., Extended Phase I studies) or complete an evaluation (e.g., Phase II studies), historical archaeologists prepare an HRER according to the instructions provided in Exhibit 6.2. Staff should also follow the background sections of the guidance in Chapter 5.
The likely areas of significance of a historical archaeological resource and its physical condition guide the amount and depth of historical research needed. It is important to develop the proper historic context and to identify the site-specific data that allow its placement within that context. Background research also involves consideration of the scope and findings of previous research on similar types of sites. Historical archaeologists use all of this information to develop important research themes and specific questions within a regional or theoretical context and to identify data requirements that can be used to measure the significance of resources.
Historical research may be conducted in collaboration with historians and architectural historians, as described elsewhere in the chapter. When conducting historical research:
- Begin by using secondary sources to develop a general context for the project area. Secondary sources may help focus the research effort by revealing useful sources of information, informants, and other details.
- Next, use primary sources, as needed, to develop suitable contextual and site-specific details.
Gathering property-specific information will usually entail some use of primary sources. The depth of research conducted in primary records will depend on the particular values a historical archaeological resource is likely to possess and the availability of secondary information about it. Some primary sources such as Caltrans “as-built” plans; U.S. Bureau of Land Management land status, mining, and old Government Land Office survey plats and notes; and historic U.S. Geological Survey quadrangle maps already should have been consulted during the identification phase discussed in Chapter 4 Sections 4-4 and 4-5 and Exhibit 4.1. CCSO staff in Headquarters can provide assistance regarding information sources located in Sacramento, such as the California State Library and California State Archives.
The historical overview, or historic context, consists of a broadly stated chronological history of the present study area, focusing on:
- Initial settlement.
- Economic development.
- Historic events that occurred in the area.
- Factors of industrial and commercial development.
- Transportation and supply networks.
- Other aspects of the area's history that may have a bearing on understanding the importance of the property under consideration.
This overview should focus on significant patterns that may be represented by the resource. Avoid lengthy discussions that lack relevance. Often historical overviews covering the same geographical area were developed in reports prepared for other documents. It is acceptable to use these overviews and focus time and effort on researching applicable themes that were not addressed in earlier reports, as appropriate (see also Chapter 4 Section 4-8.1).
A site-specific discussion should include information on property ownership, periods and types of indicated use, descriptive information concerning the physical features that existed at the site during the historic period, and modifications or disturbances to the resource that may have affected its integrity. The nature of the particular resource and its integrity will determine the type of information needed for the site-specific study. If the property appears to have good integrity and will require excavation to determine its eligibility, detailed research is normally required to provide a context for framing important questions that will be used to evaluate the research potential of the property.
Interviews with knowledgeable informants often provide essential information for determining the eligibility of historical archaeological sites. Informants also frequently provide valuable information about other kinds of resource types, particularly those occupied within living memory. In both cases, informants may provide valuable information about historic activities and resource values, the kinds of physical evidence likely to be present at a property, and the integrity of the resource. As such, it is important to make reasonable efforts to identify knowledgeable individuals, gather relevant information, and critically evaluate those data. Appropriate contacts may include current and former property owners or their heirs, local historical societies, and technical experts in fields such as the history of technology.
Professional training and interviewing experience are prerequisites for those who gather oral history information. The interviewer must observe appropriate ethical practices throughout the interview process to guard against breaches of confidentiality, to facilitate rapport with the informant, and to build his/her trust, which are all essential for effective data collection.
The following practices are recommended whenever formal interviews are conducted:
- Obtain permission before conducting any audio or videotaping of an interview.
- Give informants an opportunity to review and correct a transcript or notes taken during every interview.
- Ask informants about the confidentiality of the information they have provided and how they would like to see it reported/protected.
- If the report does not contain other confidential information, offer to provide each informant with a copy of any reports, transcripts, and tapes produced as a result of an interview.
Copies of reports going to FHWA, SHPO, and/or the Advisory Council on Historic Preservation (Council) for review and comment may not be released to the informant until after these critical agencies have received a copy and have had their regulatory opportunity to comment. No draft reports may be released.
As with any other line of evidence, critically review interview data and seek corroboration before using it in the evaluation of a resource. If using uncorroborated interviews, present the unverified information carefully, referring back to its source. Biases may be introduced as a result of a wide variety of factors including, but not limited to:
- The informant's perception of a project, interviewer, or Caltrans.
- Faulty memory.
- Deliberate misrepresentations or exaggerations.
- The way questions are phrased.
- Faulty transmission of second-hand information.
Develop research issues to determine whether the historical archaeological resource may have the potential to yield important information as required in National Register Criterion D. When developing the research issues, survey previous research concerning the type of property in question and formulate important themes or topics that the site might reasonably address and that cannot be addressed through historical research alone. The discussion should clearly explain which research themes and topics are important, why and how they are important, and how information contained within the archaeological site will illuminate and advance in specific ways our knowledge and understanding of historic themes or topics deemed significant. There should be some realistic potential to address any questions posed at the sites under investigation. Clearly defined data requirements should be the basis for assessing the potential value of any remains discovered at the property. Detailed knowledge of the social context and history of a resource is usually required to formulate research issues for historic-era occupation sites.
A historical archaeological site located within the project APE and which cannot be avoided by the proposed project must be evaluated if it is not otherwise exempt from evaluation. Additionally, such resources are often evaluated even when avoidance is possible in order to determine whether the effort and cost of avoidance is justified.
When evaluation is warranted, historical archaeological resources may be determined eligible for inclusion in the National Register under any of the four eligibility criteria, but most likely under Criterion D. See Exhibit 4.2 and National Register Bulletin 15 for guidance on applying the National Register criteria to the kinds of resources covered in this chapter. For CEQA purposes and when warranted, historical archaeological resources are simultaneously evaluated to determine whether they are historical resources for the purposes of CEQA.
How a historical archaeological site reflects any or all of the National Register criteria is determined by developing the appropriate historic contexts that seek to explain the importance of a property or group of related properties through knowledge of their historical circumstances. Historic contexts identify the period of significance, geographic scope, and historical themes that are used to assess the importance of particular types of properties. Context development should be sufficiently broad to address all potential areas of historical significance defined in the National Register criteria. However, the themes developed in a historical context should concentrate on the essential physical features or important information a resource is most likely to possess.
Evaluations of historical archaeological resources require a closely integrated assessment of both physical and historical evidence, thus a physical inspection of the property should be conducted early in the evaluation process before investing too much effort in historical research
It is rarely appropriate to conduct extensive historical research when a site is unlikely to possess sufficient integrity to either convey its significance under Criteria A, B, or C, or yield important information in history under Criterion D.
The effort spent on historical research and the assessment of physical remains should be sufficient to fully substantiate the findings of the evaluation effort, while remaining commensurate with the condition (integrity) of the site. For sites with severely compromised integrity, limit the research to gathering basic facts that will support a finding that the resource is not eligible. Always give reasonable consideration to the potential for concealed or buried historical archaeological deposits, even in cases where little surface evidence is discovered during an archaeological reconnaissance survey.
For historical archaeological sites, eligibility under Criteria A, B, or C is rare and must be appropriately analyzed in accordance with National Register guidance. Eligibility normally requires retention of the site's essential physical features and historic appearance as judged in relation to the historic context and the seven aspects of integrity (see sidebar). Loss of integrity exists on a continuum and must be viewed in a comparative framework that takes into account other surviving examples of the type of historical archaeological sites being evaluated.
|Aspects of Integrity|
|* Location||* Workmanship|
|* Design||* Feeling|
|* Setting||* Association|
For resources that consist primarily of unmodified natural settings (e.g., some TCPs), integrity is assessed in relation to the likely appearance of the property during the site’s period of significance.
Properties that appear to retain integrity, as described in National Register Bulletin 15 and Bulletin 36, should be researched to the extent necessary to determine the site’s design value and potential association with Criteria A, B, or C. Information on ownership, historic use, period of potential importance, design, and other relevant information should be sought as appropriate.
When evaluating historic or rural landscapes, take into consideration both land use processes and the components of such resources. Refer to Caltrans General Guidelines for Identifying and Evaluating Historic Landscapes, as well as to National Register Bulletin 30.
Historical archaeological sites will require some consideration of research importance to be eligible under Criterion D. In addition to historic-era habitation sites, resources such as battlefields, cemeteries, shipwrecks, and cultural landscapes have all yielded important information. For this reason, an interdisciplinary team composed of historians, architectural historians, and historical archaeologists may be required to evaluate these types of cultural resources.
To be significant under Criterion D, an archaeological site must have the potential to yield important information, not just answer simple questions such as who lived where when. Addressing important questions involves more than just filling gaps in current historical knowledge. Development of a thoughtful research design requires considering how the archaeological information might amplify or enhance our current understandings of a particular subject. As such, the historical archaeologists preparing research designs or contexts must examine previous scholarship on the subjects and take into consideration the adequacy and likely accuracy of current historical knowledge. Keep in mind, scholarly historical studies usually are written by contemporary historians and, though they may be based in part on the same primary sources that historical archaeologists employ, often arrive at fresh interpretations and insights.
In a Society for Historical Archaeology plenary session at the 1987 annual meeting, Kathleen Deagan identified five broadly defined "avenues of inquiry" that reflect the major research directions pursued within the discipline of historical archaeology (Deagan 1988). The Keeper of the National Register in National Register Bulletin 36 has recognized those research domains as important. They consist of:
- Historical supplementation.
- The reconstruction of past life ways.
- The study of cultural processes.
- The refinement of archaeological methods.
- Interpretation of the cognitive systems of past societies.
For historical archaeological sites eligible under Criterion D for their information potential, less attention is given to their overall condition than would be required under Criteria A, B, or C. There are always cultural and natural processes that alter the deposited materials and their spatial relationships. Under Criterion D, integrity is based upon the site's potential to yield specific data that address important research questions in the research design. Integrity, and its relevance to addressing research questions, will differ depending on the occupation history and land use at each site. To address important questions in history, integrity of location and materials is normally required. National Register Bulletin 36 contains extensive guidance on applying the seven aspects of integrity to archaeological properties.
Under the Section 106 PA, Caltrans, FHWA, and SHPO have identified certain classes of properties that do not require recordation or evaluation (see Chapter 4 Section 4-4.1). Exempt archaeological properties, listed in Section 106 PA Attachment 4, typically do not warrant any identification, recordation, or evaluation effort. Only Caltrans PQS and consultants meeting the PQS criteria may exempt the properties.
Included in the list is the property type “isolated refuse dumps and scatters over 50 years old that lack specific associations” that deserves some special guidance. Application of Section 106 PA Attachment 4 for exemption of this class of resource must be conducted with care. There might be research values (potential to yield significant information) under National Register Criterion D that may not be readily apparent. In situations where the potential for historical association (or lack thereof) is not directly evident, contact a qualified Caltrans historical archaeologist to discuss the property. The Caltrans historical archaeologist will then offer guidance on appropriate level of research to determine whether the property meets the exemption criteria. If the research indicates some association, such as historical occupation of the parcel where the refuse scatter is located that corresponds to the date of the assemblage, the property is not exempt and will need to be evaluated. Where no association is present, the archaeological site will meet the requirements of Attachment 4. Archaeologists may record a historical archaeological site during the identification phase that may later be found to meet the requirements for exempt properties in Attachment 4. In this situation, edit the ASR or HPSR to indicate an appropriately qualified Caltrans PQS or consultant determined the recorded property exempt from evaluation.
The key to successful implementation of Section 106 PA Attachment 4 is sound professional judgment. Questions concerning the applicability of Attachment 4 to specific historical archaeological resources should be referred to the CCSO Section 106/PA Coordination Branch Chief.
According to National Register Bulletin #15 Section IV, “If a building has lost any of its basic structural elements, it is usually considered a ‘ruin’ and is categorized as a site.” Likewise, this section of the Bulletin also states, “If a structure has lost its historic configuration or pattern of organization through deterioration or demolition, it is usually considered a ‘ruin’ and is categorized as a site.” The architectural historian, in consultation with the historical archaeologist, determines whether the building or structure is a “ruin,” as defined by National Register Bulletin #15. If, after consultation with the historical archaeologist, the architectural historian determines that the building or structure does not retain sufficient structural integrity to be classified as a building or structure, the resource is considered a historical archaeological site and an interdisciplinary approach to evaluation is used in this instance. Also see Chapter 4, Section 4-4.2.
Not all ruins of buildings and structures within a project APE require study. As stipulated in Section 106 PA Attachment 4 the following are exempt from evaluation:
- Foundations and mapped locations of buildings or structures more than 50 years old with few or no associated artifacts or ecofacts, and with no potential for subsurface archaeological deposits.
- Building and structure ruins and foundations less than 50 years old.
However, they may not be exempt, if they are part of any larger historic or potentially historic property (see Section 106 PA Attachment 4).
When there may be associated archaeological components, appropriately qualified historical archaeologists who meet the PQS standards for that discipline record and, if applicable, evaluate ruins of buildings and structures. Historical archaeologists with requisite coursework and training in building construction technique history, established by submitting documentation of that training to the Headquarters Cultural and Community Studies Office (CCSO), in consultation with architectural historians, also may evaluate under Criterion D when the information is contained within the constructed remains of the building.An interdisciplinary approach is used in this instance. Also see Chapter 4, Section 4-4.2.
Excavating historical archaeological sites is an expensive and time-consuming activity that may sometimes be avoided. Loss of integrity, a preponderance of informative surface archaeological deposits, the results of prior excavation work, or sufficient historical records and information regarding that type of site may all provide adequate grounds for a finding for or against eligibility without having to excavate. Even if some buried deposits are anticipated, the importance of some historical archaeological sites (particularly those that consist largely of surface deposits) often can be addressed without excavation. For example, a construction camp in Inyo County was determined eligible for inclusion in the National Register under Criterion D based solely on the abundant and relatively intact surface deposits found there. Make the argument for or against eligibility of a historical archaeological site without test excavation in the HRER.
Historical archaeological resources that have clearly lost their integrity and lack historical importance or the ability to address important research topics should be determined as not eligible for inclusion in the National Register. In such a situation, document the lack of integrity in the HRER. For instance, simply stating that an orchard was planted on top of the location of a former adobe is not sufficient. On the other hand, information from the landowner that heavy equipment churned the earth to a depth of five feet to prepare the ground for planting is the type of important detail needed to support the lack-of-integrity statement. This fact then would be considered in relationship to the expectation for archaeological deposits, based upon knowledge of similar site types and potential for effect (i.e., is there an expectation for deposits below five feet and what is the depth of construction impacts).
In some cases, evaluation may be unnecessary if the value of the site appears to be limited to its research potential, and an Extended Phase I (XPI) investigation reveals that the boundaries of the property are outside of the area directly impacted by project construction. See Section 6-6 for a discussion of the justification for an XPI study, as well as Exhibit 5.2.
Where evidence exists that demonstrates the site possesses integrity and archaeological data potential, such as through remote sensing (see Exhibit 5.10) or knowledge of similar site types and degree of disturbance, one may make an argument that a site is eligible based on its potential to yield information. The potential to yield information must be demonstrated in the HRER in a well-developed, rigorous research design that considers the site-specific context with comparisons to similar historical archaeological sites.
The argument for eligibility based on information potential with no test excavations should be used sparingly. Save it for situations where property access problems would delay completion of the environmental document. It might also be used when the project’s effects to the site can be reasonably assessed and there is enough information on integrity to make a final effect determination for the site.
Evaluation of historical archaeological sites without excavation is documented in the HRER. Caltrans PQS at the Co-PI level and consultants who meet the same qualifications may perform the evaluations with peer review by a PI-level historical archaeologist.
In some cases where the provisions of the Section 106 PA do not apply, such as on projects involving tribal lands or state funded projects, it may be appropriate to document in a Letter Report historical archaeological sites that are not eligible for inclusion in the National Register. See Exhibit 6.1 for format of a letter report. Most of these resources will be exempt properties as described in Section 106 PA Attachment 4 and discussed in Chapter 4 and Section 6-4.2, but appropriate historical research and field survey should be conducted to ensure the resource meets the requirements of Section 106 PA Attachment 4.
A finding that a historical archaeological site is not eligible for inclusion in the National Register, at this stage, may be a result of any one of the following factors:
- Demonstrated loss of site integrity.
- Absence of historical associations or important design value.
- Demonstrated lack of archaeological research potential.
While an archaeological survey may be able to record information in the field to document a loss of site integrity, the appropriately qualified historical archaeologist must evaluate the latter two qualities. If it is determined that a historical archaeological site meets at least two of these three factors, include the results of the evaluation and justification for its conclusions in a Letter Report.
Many historical archaeological resources are likely to fall into this category of ineligibility. However, be careful to avoid blanket assumptions as to lack of historical associations or archaeological research potential until adequate information regarding a resource's historic context and associations can be established. For instance, unassociated tailings piles, isolated refuse dumps, mine test pits, and rock walls are all likely to be determined not eligible for inclusion in the National Register. However, some examples of those resource types, such as a rock wall delineating the boundary of a Mexican rancho, may be potentially eligible because of their important historical associations with themes developed in a historic context. They also may be part of a larger historic property (i.e., a contributor to an eligible property).
A Caltrans PQS certified at the Co-Principal Investigator level or higher must peer review the draft Letter Report. Caltrans PQS carefully review the document prior to submission to FHWA and SHPO to ensure timely consideration and approval by those agencies. Peer review ensures that the Letter Report:
- Follows the format and content guidelines provided in Exhibit 6.1
- Meets professional standards in field methods, site recording, and reporting
- Fulfills the obligation of the identification and evaluation steps required by 36 CFR §800.4(b) and (c).
Fifteen (15) working days are normally allowed for peer review. Also see Section 6-16.1.
Following peer review, and any necessary revisions, the report preparer signs the title page of the final Letter Report. Then, Caltrans PQS at the Co-Principal Investigator level or higher reviews for approval either the Caltrans staff- or consultant-prepared final Letter Report. Review ensures that the report is acceptable and that the maps depicting the Study Area and the area surveyed are accurate. If a Caltrans PQS has not prepared the report, the responsible PQS indicates review and approval by signing the title page of the report. The DEBC then reviews and formally approves the Letter Report by signing the title page.
Upon approval, attach the Letter Report to the HPSR or HRCR as a technical document demonstrating the property is not eligible for inclusion in the National Register.
Where possible, evaluate historical archaeological sites without excavation because of the cost and time commitments associated with all types of test excavation programs. Furthermore, excavations by their very nature destroy sites. Chapter 5 discusses XPI and Phase II studies in detail and Exhibits 5.2, 5.3, 5.4, and 5.5 provide the format and content of these proposals and reports. This section focuses on the differences inherent when dealing with historical archaeological sites.
When the evaluation of a historical archaeological site cannot be completed based on historical research alone, however, test excavations need to be conducted to:
- Establish the boundaries of the resource relative to a project's direct impact area (XPI Studies or XPI).
- Evaluate the research potential of the property (Phase II Studies).
Test excavations usually are conducted when their results are essential to determining the site’s ability to address important research topics. They may be equally important for understanding a project’s effects to the site, specifically for determining locations of intact portions of the site relative to the Direct APE for the proposed project. Testing is not warranted for historical archaeological sites that:
- Lack integrity and/or clearly defined historical associations.
- Lack research potential (e.g., sites with little or no cultural deposits).
- Can be adequately evaluated using historical information and surface inspection.
XPI and Phase II studies follow similar procedures, differing primarily in their scope and objectives. Chapter 5 and Section 6-6.2 discuss the scope and objectives of each type of study. Because archaeological excavations usually require large commitments of time and public expense, both XPI and Phase II testing procedures must be justified in the proposal. See Section 6-7 for a discussion of how to prepare proposals for these studies. Planning and conducting archaeological testing programs at historical archaeological sites follow many of the same procedures already considered in Chapter 5. Unique requirements for work at historical archaeological sites are discussed in separate sections covering pre-field preparation and fieldwork (Section 6-8), field safety (Section 6-8.2), laboratory analysis (Section 6-9), and reporting requirements (Section 6-10). See also Exhibit 5.9 which contains the Excavations pre-field checklist, Exhibit 2.6 regarding safety, and Exhibits 5.3, and 5.5 that contain reporting formats.
When excavation is required, allocate adequate time for testing programs. Assuming the work is a typical XPI study at one site, and adequate project mapping is available at the inception of that work, the average XPI study, including excavation and report completion, takes six months. Based on the same criteria, Phase II investigations normally require 12 months. Special circumstances such as limitations on rights of entry or special restrictions associated with endangered species or seasonality may significantly lengthen these time frames. Exhibit 2.3 contains estimates of the time and effort required to complete such excavations.
The objectives of a test excavation program always need to be stated clearly and justified, with specific thresholds defined to establish when the work can be considered to have met those goals. An XPI study may be expanded into a Phase II testing program in cases where the proposal has been specifically designed to accommodate that eventuality. It is often helpful to prepare a combined XPI/Phase II proposal in cases where time is of the essence and there is a reasonable expectation for that outcome.
XPI studies of historical archaeological sites are small-scale archaeological investigations with narrowly defined goals. Conduct these investigations solely to determine the presence or absence of cultural deposits and whether the deposits extend into the project’s Direct APE.
An XPI study typically is undertaken to establish the presence or absence of intact historical archaeological deposits within the project’s Direct APE. This type of study occurs when deposits are expected but cannot be confirmed or precisely located using historical research and surface inspection alone.
While XPI studies are not carried out in order to determine whether the site is eligible for inclusion in the National Register, data (or the lack of it) recovered from an XPI study may sometimes be used to determine that the portion of a site within the Direct APE would not contribute to the eligibility of the site, should it ever be found to be eligible for the National Register. One should conduct a Phase II investigation when a historical archaeological site is known or likely to contain subsurface deposits within the project’s Direct APE, and those deposits have the potential to address important research topics. Normally Phase II studies are also needed to complete the evaluation of a site when the results of an XPI study are positive.
The premise for a XPI study is that there is a fairly low, but nonetheless possible, chance that potentially important archaeological deposits extend into the project’s Direct APE. The typical XPI study will establish whether there are potentially significant archaeological deposits in the project’s Direct APE. Lack of potential for significance may be predicated on the absence of cultural deposits or a substantial loss of integrity. In the former case, re-draw site limits; in the latter case, or for management purposes, establish the area subject to the XPI test as a noncontributing element of the larger site. The second scenario is an eligibility determination that Caltrans will submit to SHPO for their concurrence.
Given the expense and length of time required for full Phase II archaeological excavation programs, such studies are used to evaluate historical archaeological sites only when:
- There is a clear potential that the undertaking will affect the site, and
- The site's research value cannot be adequately assessed using information from its surface manifestations.
The decision to conduct a historical archaeological test excavation program is based on the anticipated presence of intact, information-bearing historic-era archaeological deposits in the project’s Direct APE.
The research potential of a historical archaeological site is determined by assessing the:
- Identifiable historical associations.
- Diversity, abundance, and types of cultural materials expected to be present.
- Anticipated depositional integrity of the archaeological site.
The absence of identifiable associations and/or research potential is typically documented without excavation and is based on historical research and surface inspection. Where a site is likely to contain important data, but the presence of intact deposits in the Direct APE is uncertain, an XPI study may be more appropriate. Some sites consisting largely of surface deposits that may be potentially eligible for their research value can be effectively evaluated without excavation, as described in Section 6-4.2 above.
Phase II excavations are appropriate when there is likelihood that reasonably intact subsurface archaeological deposits clearly can be associated with a historically documented occupation or activity. Sites that lack clear historical associations are not likely to warrant excavation because there is little prospect that they can address any important questions in history. In a similar vein, sites that may possess a limited range of cultural materials, or materials that cannot be associated with an identifiable deposit or feature, are also unlikely to address important research topics. Use surface evidence and the types of historical activities known to have taken place at a site to assess this potential.
Conduct a Phase II archaeological study to:
- Evaluate whether the resource is eligible for inclusion in the National Register.
- Acquire sufficient information about the site to assess the project effects when plans are sufficiently developed. .
Normally, the Phase II study should address the entire resource, however excavations should focus on areas known to be within the Direct APE (see Chapter 5 Section 5-6 for further guidance).
When an XPI or Phase II study is justified, the PI historical archaeologist must prepare, or directly supervise the preparation of, an excavation proposal. Likewise, the historical archaeologist is responsible for implementing the work. When XPI or Phase II studies involve sites occupied by Native Americans during the historic era, either a historical archaeologist or an appropriately trained prehistoric archaeologist may prepare the proposal.
The excavation proposal must include a:
- Concise historical context.
- Realistic and site-specific research design.
- Work plan.
The level of detail required for a given proposal will depend on the:
- Type of work that is proposed (XPI or Phase II).
- Complexity of the resource.
- Scope of anticipated project impacts to that resource.
In general, XPI study proposals should be much simpler than those prepared to justify Phase II studies. Exhibits 5.2 and 5.4 contain supplementary guidance on scope and contents of proposals for XPI and Phase II studies. All proposals should include specific provisions for obtaining necessary entry rights and permits.
Work plans in the proposals should include provisions for curating recovered specimens, as well as field notes, photographs, and reports. Give serious consideration at the proposal stage as to what materials will be subject to retention, discarded, or not collected during field excavation. It may be entirely appropriate to discard many materials with low research value (e.g., nails, non-diagnostic fragments of glass, etc.) once they have been thoroughly catalogued for purposes of data analysis. In such cases, the proposal should clearly explicate discard policies that will be employed during fieldwork. It is generally inappropriate to curate collections generated from XPI studies unless they produce positive results that will lead to a Phase II study.
Guidelines for Curation are found in Curation of Federally-Owned and Administered Archeological Collections (36 CFR Part 79, originally published in the Federal Register, Vol. 55, No. 177, September 12, 1990). California has also adopted state curation guidelines that should be consulted when the plan is being prepared. District management, usually the DEBC, reviews and approves the curation plan.
When an XPI study is justified at a historical archaeological site, the proposal follows the same format (Exhibit 5.2) as would be prepared for a prehistoric archaeological site. It states why the XPI study is needed, the field methods to be used, and the basis for determining when the study goals have been met and fieldwork can cease. Since an XPI investigation should be limited in scope, the proposal should be brief.
XPI Proposals should include the:
- Reasons the study is needed.
- Goals of the investigation.
- Field and laboratory methods to be used.
- Thresholds used to establish when the study has achieved its objectives.
- Availability of appropriately qualified personnel, whenever possible.
- Schedule for completing the work.
The introduction to the proposal should indicate the study's goals and why an XPI, rather than a Phase II, study is appropriate. This document should supply a historic context, site description, and a brief discussion of the resource's potential importance in relation to current research topics.
Define the methods to be used in the scope of work. Flexibility is most important, and a combination of mechanical excavation, surface scrapes, auger holes, shovel test pits, rapid recovery units, and control units may be required. Since minimal recovery of archaeological materials is anticipated, proposing only limited laboratory work is appropriate. Include curation plans in the event that potentially significant deposits are encountered and a follow-up Phase II study is needed. State explicitly whether materials will be curated.
Protracted discussion of theoretical research questions in the XPI is inappropriate and not necessary.
Phase II proposals require more complete development of a research context against which any remains that are encountered will be measured. Because such work is conducted with the expectation that potentially significant deposits and features may be found, develop research questions to cover all expected areas of potential importance. Define the explicit data requirements for each topic.
Excavation efforts should be focused on that portion of the site within the Direct APE; however, particular research objectives may direct excavations to specific areas, components, or features within the site. Other features may not warrant any effort beyond noting their presence.
A PI-level historical archaeologist must prepare, or directly supervise the preparation of, the Phase II proposal, in consultation with historians or architectural historians or other specialists if a project team has been formed. In cases where excavation is planned at a historical archaeological site associated exclusively with historic Native American use, either an appropriately qualified prehistoric or historical archaeologist can prepare the Phase II Proposal (see Exhibit 5.4 for guidance).
The Phase II Proposal should include:
- Need for the Phase II study.
- Goals of the investigation.
- Field and laboratory methods to be used.
- Historical research methods.
- Research Design that explains the data needs to address important research issues.
- Thresholds used to establish when the study has achieved its objectives.
- Availability of appropriately qualified personnel, whenever possible.
- Schedule for completing the work.
- A curation plan.
XPI and Phase II Proposals that describe the excavations to be performed at historical archaeological sites should follow the general format and content guidelines found in Exhibits 5.2and 5.4. Complete a revised archaeological site record and append it to the report if additional information is recovered beyond that recorded in the ASR. For example, additional information may include redefined limits or changed nature of the archaeological site.
Caltrans PQS certified at the PI level for historical archaeology must peer review the draft XPI or Phase II proposal to ensure it meets professional standards (see Section 6-16 for further information on peer reviews). Submit requests for peer review to EBCs who supervise Caltrans PQS PI-level historical archaeologists either in district environmental branches or in the Headquarters CCSO. The peer reviewer normally has up to fifteen (15) working days to complete the review. The originating DEBCs may allow longer review periods at their discretion.
Following peer review, and any necessary revisions, the report preparer signs the title page of the final XPI or Phase II Proposal. If a Caltrans PQS has not prepared the proposal, the responsible PQS indicates review and approval by signing the title page. The DEBC then reviews and formally approves the XPI or Phase II Proposal by signing the title page. Upon approval, the appropriately qualified historical archaeologist may implement the proposal.
Pre-field preparation includes the activities outlined in the excavation checklist in Exhibit 5.9, such as securing:
- Access rights.
- Underground service alert.
- Detailed project mapping.
- Appropriately qualified crew.
These requirements largely duplicate those discussed in Chapter 5. However, some additional considerations bear mention here with regard to excavations at historical archaeological sites.
Testing historical archaeological sites requires a great deal of methodological flexibility to yield maximum information. Design the proposals to allow considerable freedom in choice of field methods, especially with regard to excavation unit size and shape. Fieldwork should then follow the approved proposal.
Field methods for testing historical archaeological sites often differ from those used to sample prehistoric archaeological sites. The types of sampling strategies commonly used at prehistoric archaeological sites (particularly random sampling) are not very useful when investigating historical archaeological sites, since sample units may more appropriately be the identified features themselves. It may be necessary to clear vegetation from broad areas of the site, or features within the site, in order to locate features or artifact concentrations before actual excavation.
Some historical archaeological sites require exploratory backhoe trenches or grading to provide information on site stratigraphy and feature location. Trenching may be an essential first step for investigating sites with long occupations where there may be buried components, flood deposits, or other vertically stratified elements. Others (such as single component sites) may require shallow block exposures or broad excavations that have the potential to reveal a maximum number of subsurface and surface features.
Subsurface features may be located by means of trenches, shovel tests, backhoe scrapes, or probes with metal rods in search of changes in soil compaction, color, or constituents. They may also be discerned by using metal detectors, remote sensing, and other geophysical techniques, although such procedures require the use of experienced analysts. The topography of the site may also provide clues to the presence of subsurface features. Once the important features of a site are located, controlled test units may be appropriate to maximize the information yield with a minimum amount of disturbance.
Surface remains should be thoroughly examined when the site is recorded and an accurate sketch map prepared for the site record. For XPI and Phase II excavations, the site must be mapped using standard archaeological techniques, usually with a transit and stadia rod. Sub-meter accuracy Global Positioning System (GPS) devices may be used as an alternative mapping method. The surface features of the site and all excavation units should be plotted and tied to a permanent datum established outside the transportation project's Direct APE.
A PI-level historical archaeologist who has the authority to make decisions should be on site during the work. Alternatively, the PI may supervise a Co-PI historical archaeologist or a prehistoric archaeological Lead Archaeological Surveyor. In cases where the historical archaeological site is associated exclusively with Native American use, a PI-level prehistoric archaeologist may direct the work. Section 106 PA Attachment 1 describes the qualification requirements for historical and prehistoric archaeologists and Exhibit 1.5 provides in table format the PQS levels required for archaeological activities.
If there is no Native American component to the historical archaeological site, coordination with local Native Americans, and the presence of a Native American monitor is not sought. A Native American monitor is required when there are sites with multiple components that include Native American elements. See Chapter 3 for guidance.
Health and safety issues that should be considered carefully prior to every project are discussed in Chapter 4, Section 4-6.3. Chapter 2 in the Caltrans Survey Manual describes standard field safety precautions such as traffic management, first aid, and other routine practices as outlined in Exhibit 2.6.
A tailgate safety meeting tailored to the specific needs of each excavation project must be conducted at the inception of and at intervals during every field excavation project.
In addition to the standard safety precautions, such as shoring and entry into confined spaces common to excavations at all types of sites, work at historical archaeological sites may need to account for a variety of special hazards. Those hazards include both pathogenic and chemical contamination found at some historical archaeological sites. For example, privy pits may contain pathogenic organisms. Industrial sites often contain areas with hazardous chemicals, such as the milling area at a mine, or obscured dangers, such as mine shafts. With the exception of mine shafts, hazards can often be controlled or avoided by appropriate hygienic practices and protective equipment such as rubber gloves and masks. For example, washing hands before eating should be standard safety practice whenever work occurs in potentially contaminated soils.
If there is a reasonable chance that hazardous wastes may be encountered during an archaeological excavation, a Certified Industrial Hygienist (CIH) should prepare a health and safety plan prior to initiation of the excavation. Alternatively, an archaeologist with 40-hour Hazardous Waste Operations and Emergency Response (HAZWOPER) training may prepare the document. Regardless of who prepares the document (CIH or archaeologist with HAZWOPER training), the site safety officer should be trained appropriately and given authority to implement provisions of the safety plan. To assess potential risks, consider pre-testing by a hazardous waste consultant. If appropriate, District and Headquarters Hazardous Materials Coordinators can provide assistance in procuring the services of CIHs and determining the presence of hazardous wastes.
Work at heavily contaminated sites is rarely justified and generally should be avoided. This is because the cost of testing contaminated sites is often excessively high, involving not only expensive field safety procedures, but also the cost of decontaminating recovered materials following their retrieval.
Laboratory work normally entails:
- Washing or preparing samples (if necessary).
- Identifying materials, artifact types, and date ranges attributable to those items.
- Quantifying artifacts (total pieces and minimum number of individual items).
- Where appropriate, suitably packaging and conserving materials that will be retained for permanent curation.
In keeping with the procedures specified in the excavation proposal, materials with little research value should be cataloged and discarded. This minimal processing is usually all that is appropriate for XPI studies.
Phase II laboratory work normally goes beyond the minimal processing described above to include some specialized analyses. Those special analyses should be undertaken only to the extent needed to determine whether the data contained in the site have the potential to address the research questions posed in the Phase II proposal. If the expertise does not exist in house, it may be necessary to retain consultants with specialized expertise in faunal analysis, industrial processes, and other topics to achieve the research design’s goals. Materials should be cataloged according to standard functional categories (with modifications as appropriate for the site) in order to facilitate the site comparisons often necessary for eligibility determinations as well as to guarantee the future comparative value of the work.
Caltrans uses the Historical Resources Evaluation Report (HRER) to document evaluations of historical archaeological resources. The HRER is also used to evaluate built-environment resources as discussed in Chapter 7. Separate reports may be prepared for the same project depending on resources present and time frames involved. When excavation is required to evaluate a site, an XPI or Phase II proposal precedes the HRER. The nature of the values a resource may possess will determine the kinds of expertise needed to evaluate it. Coordination with Caltrans architectural historians or ethnographers, for example, is appropriate and necessary for resources with those values. Assess the historical archaeological resource for all potential areas of significance. The format and content of an HRER will depend on the types of resources that are being evaluated and the degree of archaeological excavation. See Exhibit 6.2.
The HRER contains a concise discussion of the reasons each historical archaeological site is or is not significant. Information required for historical archaeological sites includes:
- Site type.
- Historical overview.
- Site-specific historical information.
- Site description, including size, depth, structure/organization, features, the nature of the cultural deposits, and a discussion of site boundaries and the methods by which they were defined.
- Integrity of the site as well as its immediate environment.
- Summaries of known archaeological data within the site.
And for eligible sites:
- Applicable National Register criteria and areas of significance (if eligible under National Register Criterion D, emphasize how the data contained in the site may address important research issues).
- Period and level of significance.
- Contributing and non-contributing elements.
- National Register boundaries.
The statement of significance should normally address the entire site. It should also consider appropriate historical themes such as commerce and industry, transportation, or exploration and settlement, to name but a few. National Register Bulletin 16A and the Office of Historic Preservation’s “Instructions for Recording Historical Resources” contain a list of "areas of significance" from which historical themes can be derived. Sites likely to have research importance under National Register Criterion D will require more refined discussions of important research topics. Provide a summary of the potential research contributions to support eligibility under this criterion. Consider the seven aspects of integrity, their relative importance, and their ability to convey a resource’s significance in the eligibility discussion. Because Caltrans simultaneously evaluates these resources to comply with CEQA, include a statement that Caltrans also has determined that the site is a historical resource for purposes of CEQA.
The HRER may also make the case for eligibility of a historical archaeological site without test excavation. In this situation, the HRER presents enough information to support a determination of potential significance, or lack thereof. HRERs that document eligibility without excavation are most commonly used for sites that either have lost integrity or are important for reasons other than their research significance. As stated above in Section 6-4.3, where evidence exists that demonstrates the site possesses integrity and archaeological data potential, an argument may be made that a site is eligible for inclusion in the National Register based on its potential to yield information.
The amount of detail required in an HRER will vary considerably. For example, a lengthy discussion of nineteenth century shipbuilding and subsequent uses of the site was required to establish that a San Francisco shipyard had lost integrity. In a different case, research documented that the meager remains of a domestic occupation site were associated with a shopkeeper’s 1930s house. Not only were the remains disturbed, but also their historic associations and context indicated that the potential for the site to yield important information was lacking. The document evaluating that historical archaeological resource was only a few pages long.
The finding that a historical archaeological site has few or no historical associations or archaeological significance must be documented adequately enough to support the federal agency’s (Caltrans, on behalf of FHWA under the Section 106 PA, or another federal agency) determination that the site is not eligible for inclusion in the National Register. For Caltrans (or any other lead agency under state law), this is a determination that the site is not a historical resource for the purposes of CEQA. The level of detail should be adjusted to fit the circumstances. Information included in the HRER and supporting documentation should be thorough enough to establish adequately the historical context within which the resource is evaluated, including site-specific information and the reasons why the site is not eligible.
When buildings, structures, or objects are components of a cultural resource that contains archaeological deposits and/or features, the evaluation of the built and archaeological elements is combined in a jointly prepared HRER. In such cases, a team composed of architectural historians and historical archaeologists will collaborate and share responsibility for the evaluation. A team leader shall be assigned to coordinate the research effort and report preparation.
When the cultural resource contains predominantly historical archaeological components, the historical archaeologist will normally be the team leader. When the resource appears to contain predominantly historic-era built resources such as buildings, structures, objects, districts, or non-archaeological sites, the architectural historian is normally the team leader.
In both situations, the architectural historian will have primary responsibility for evaluating a resource’s built elements for significance related to criteria A, B, and C, while the historical archaeologist will have primary responsibility for findings about the archaeological elements and values related to Criterion D. The outcome of the collaborative effort will either establish by consensus that a resource is not eligible for inclusion in the National Register, or define one or more areas of significance to support a National Register eligibility determination.
For combined work, the citation and reference style shall be determined by the principal author and the preponderance of resources; e.g., if resources are primarily historical archaeological sites and, therefore, the archaeologist is the principal author, the historian’s portion of a combined document should conform to the scientific style of citation. However, if historical archaeologists and historians or architectural historians separately prepare two HRERs that then are merged, the HRERs do not need to conform to the same citation and reference style.
When archaeological properties contain both prehistoric and historic-era components, the site may be evaluated in a jointly prepared Archaeological Evaluation Report (AER). In such cases, a team composed of prehistoric and historical archaeologists will collaborate and share responsibility for the evaluation. Historians and ethnographers may be involved as circumstances warrant. A team leader shall be assigned to coordinate the research effort and report preparation. When the cultural resource contains predominantly historical archaeological components, the historical archaeologist will normally be the team leader. When the resource appears to contain predominantly prehistoric components, the prehistoric archaeologist is normally the team leader. The outcome of the collaborative effort will either establish by consensus that a resource is not eligible for inclusion in the National Register, or define one or more areas of significance to support a National Register eligibility determination.
A Caltrans PQS PI-level historical archaeologist must peer review all draft HRERs that involve historical archaeological sites, as well as XPI or Phase II Proposals and Data Recovery Plans. Caltrans PQS for architectural history must peer review appropriate sections of combined HRERs that involve built environment resources, as described in Chapter 7. Ideally, when HRERs address both historical archaeological and built resources, a Caltrans PQS who is outside the discipline of the primary author who prepared the HRER should conduct a peer review to ensure the HRER adequately considers the full range of potential historical associations and values that may be associated with the subject resources.
Peer reviewers ensure that the HRER meets the needs and expectations of outside review agencies, such as SHPO. The HRER must:
- Adequately discuss the scope of evaluation efforts.
- Present substantive and concise information regarding the evaluation efforts.
- Contain a definitive statement of whether the evaluated cultural resource meets National Register criteria or is a historical resource for the purposes of CEQA (see Exhibit 2.17 for guidance on summary paragraphs).
- Identify specific areas of significance, and if under Criterion D, the information the site may contribute.
- Include appropriate graphics, such as mapping, excavation drawings, and photographs.
Districts without appropriate Caltrans PQS may request peer review by appropriately qualified staff at CCSO or in other districts. Make the request to the CCSO Chief or appropriate DEBC. The Caltrans PQS typically have fifteen (15) working days to complete the peer review. The originating DEBCs may allow longer review periods at their discretion. If the peer reviewer does not provide comments to the author within this time frame, the HRER is considered adequate and the DEBC may approve it, as described below.
Following peer review, and any necessary revisions, the report preparer(s) takes into account timely comments on the draft, prepares the final HRER and signs the title page of the final HRER. Then, Caltrans PQS reviews for approval either the Caltrans staff- or consultant-prepared final HRER. Review ensures that the report is acceptable and that the maps depicting the Study Area and the area surveyed are accurate. If a Caltrans PQS has not prepared the report, the responsible PQS indicates review and approval by signing the title page of the report. The DEBC then reviews and formally approves the HRER by signing the title page. The accompanying transmittal memo should summarize the major findings in the HRER. If the memo transmitting the HRER to the DEBC for approval made recommendations concerning the resource, this memo also should be sent to the CCSO Section 106 Branch Chief (for federal undertakings).
The requesting DEBC approves all HRERs, which then become part of the summary document, the HPSR. See Exhibit 6.2 for the appropriate HRER format.
When Caltrans PQS from Headquarters CCSO prepare the HRER, the final report is sent to the district, and district staff prepare copies. The number of copies should include copies for transmittal to FHWA and SHPO, for district and CCSO files, plus any additional copies the district requires. The historical archaeologists and/or architectural historians who prepared the HRERs may submit electronic files to the requesting district to facilitate report production and reduce mailing times.
When the district prepares HRERs, the HRC should ensure that the appropriate number of copies are made and attached to distribution copies of the HPSR or HRCR, including a copy to CCSO, as described in Exhibit 2.11. Send a final copy to the appropriate Information Center only after SHPO has concurred on eligibility determinations. If state-owned resources are included in the HRER, send a copy of the transmittal memo summarizing the state-owned resources, including name, location and National Register eligibility status, to the Chief, Built Environment Preservation Services Branch for PRC §5024 purposes.
When a resource within the APE can be protected from adverse effects, the resource and a surrounding buffer is designated an Environmentally Sensitive Area (ESA) and preserved in place. Protecting historical archaeological sites through the use of ESAs is similar to protection of prehistoric archaeological sites using ESAs. Consult Chapter 5, Section 5-7, Exhibit 2.7 and Section 106 PA Attachment 5 for further guidance.
As a result of concerns expressed by Caltrans Headquarters, Regional and District management, the California Transportation Commission, FHWA and regulatory agencies over the appropriateness of certain mitigation expenditures, Caltrans established a policy for internal independent peer review of all environmental mitigation commitments expected to exceed $500,000 per project. This review is intended to confirm that the mitigation is cost effective and that it is commensurate to the scope of the undertaking and to the type and significance of the historic properties.
Data Recovery Plans, Treatment Plans, excavations and other proposed mitigation measures that identify costs of $500,000 and above for the undertaking as a whole must be reviewed by the CCSO Chief, under delegation by the Chief, Division of Environmental Analysis, per memo of January 28, 2005.
The CCSO Chief will complete the review within fifteen (15) working days from receipt of the mitigation documentation. This review is intended to provide independent analysis to ensure that the mitigation is cost effective and commensurate to the scope of the undertaking, the type and significance of the historic properties, and that the Data Recovery Plans are consistent with the requirements of Section 106 PA Attachment 6. The District Environmental Branch Chief will take the CCSO Chief's comments into consideration prior to approving mitigation costs of $500,000 and above.
A variety of different treatment procedures may be appropriate when a significant historical archaeological site may be adversely affected by a project. Caltrans develops appropriate treatment measures in consultation with SHPO (see Chapter 2 for guidance on SHPO consultation procedures and legal documents). The scope of possible mitigation measures will depend on the reasons why a historic property meets National Register criteria and the nature of the project’s effects. Caltrans typically uses data recovery programs to recover the information values of sites significant under National Register Criterion D. Other kinds of research programs and public interpretation may be needed to offset the loss or impairment of historical archaeological sites that were determined eligible for the National Register under other criteria.
When data recovery is stipulated in a Memorandum of Agreement (MOA), Caltrans develops a Data Recovery Plan (DRP) in accordance with Section 106 PA Attachment 6 to describe in detail how the important information from a site will be recovered, analyzed, and disseminated to both professional and public audiences. The Advisory Council on Historic Preservation has published Recommended Approach for Consultation on Recovery of Significant Information From Archaeological Sites (Federal Register, May 18, 1999, 64(95): 27085-27087) that should be consulted when preparing such plans.
In addition to these foreseeable treatment approaches, it may sometimes be prudent and necessary to prepare Treatment Plans. Treatment Plans would be appropriate when time is of the essence or access to historical archaeological sites cannot be reasonably obtained until late in the project development process. Caltrans has successfully used Treatment Plans on several large urban projects in order to plan for the discovery of important historical archaeological sites buried under urbanized areas. Treatment Plans are discussed in Section 6-12.2.
Data Recovery Plans (DRPs) for historical archaeological sites should focus on the retrieval of the archaeological values that make the site significant and will otherwise be lost. Those values must be expressed as, or relate to, important research questions in historical or cultural topics. The DRP is appended to a project MOA to complete the Section 106 process. The DRP must conform to Section 106 PA Attachment 6, and it should be based on information derived from historical research and from any previous test excavation. In addition, National Register Bulletin 36 provides useful information for preparing DRPs for historical archaeological sites. Exhibit 5.6 contains the format and contents for a DRP.
Data recovery typically focuses on the area that will receive direct impacts. However, some work outside of the direct impact area may sometimes be required to address particular research values. For example, in order to address questions about a specialized community’s organizational principles and practices, it may be necessary to gather information on features outside of the direct impact area. However, the emphasis of the work must be on the site’s research values that will be directly affected by the project.
Planning, pre-field preparations, excavation procedures, laboratory work, and analyses for a data recovery program differ from those employed for a test excavation mainly in their scope. The goal of a data recovery program is to recover the important information threatened by the project and thoroughly analyze and interpret that material for the benefit of public and professional audiences.
For some kinds of historical archaeological resources, detailed recordation may be the appropriate approach for capturing the site's threatened information. Documentation in forms such as photography, scaled drawings, maps, and descriptive text can be used to preserve important information associated with the ruins of some buildings or structures, ditch systems, roadbeds and trails, rock walls, and other features. For those situations, the Finding of Effect document or Section 106 consultation letter can succinctly outline the proposed data recovery methods.
A PI-level historical archaeologist must prepare the DRP for a historical archaeological site. However, in cases involving a historic Native American activity area, an appropriately qualified prehistoric archaeologist may prepare the DRP. As necessary, consult with a qualified architectural historian and other experts during the development of DRPs. For historical archaeological sites that are significant under criteria A, B, or C for reasons other than research potential, the DRP must be coordinated with other types of mitigation or treatment measures. Caltrans PQS at the PI-level for historical archaeology must peer review the DRP. Chapter 5, Section 5-8.3 contains more guidance on peer review procedures and distribution of DRPs.
If the work will be conducted by a consultant, a Caltrans PQS at the PI or Co-PI level for historical archaeology reviews DRPs involving investigation of historical archaeological sites and provides advice to members of the contractor selection committee. Caltrans PQS at the PI or Co-PI level for historical archaeology should monitor historical archaeological excavations conducted by consultants who meet the appropriate qualifications outlined in Section 106 PA Attachment 1.
Treatment Plans essentially compress identification, evaluation, and treatment into a single process. While this approach results in significant efficiencies, it can be justified only in situations where the normal process cannot be followed.
Caltrans should prepare Treatment Plans in situations where it is foreseeable and likely that historical archaeological sites that are potentially eligible for inclusion in the National Register will be encountered, but there are overriding practical reasons why those sites cannot be tested prior to construction. For example, a Treatment Plan may be appropriate in an older neighborhood covered by modern urban development because access to buried deposits cannot be reasonably obtained before built properties have been acquired and razed in preparation for highway construction. Treatment Plans in these situations serve as detailed plans for how discoveries will be managed. As such, they provide the basis for a formal agreement, such as an MOA or a project-specific Programmatic Agreement.
Caltrans should consult with FHWA and the SHPO prior to initiating the Treatment Plan approach. Such consultation is particularly important because the preparation of a Treatment Plan requires a substantial investment of effort in planning and background research to prepare for discoveries and associated contingencies.
Treatment Plans minimally should contain the:
- Detailed historic context.
- Detailed research design that identifies the specific types of important archaeological deposits and features likely to be encountered.
- Methods that will be used to locate them.
- Specific evaluation criteria and procedures.
- Detailed plans for recovering, analyzing, and disseminating their important data.
When preparing Treatment Plans, it is crucial to develop explicit expectations and evaluation thresholds that can be used to determine which deposits and features are eligible and thus merit prescribed treatment measures.
Treatment Plans have much in common with DRPs because they are prepared only in cases where it is anticipated that data recovery will be required. The major difference between the two documents is the level of information available to guide the planned data recovery. Exhibit 5.6 contains suggestions regarding the format and content for DRPs, that essentially are the same for Treatment Plans. The standard review policies for DRPs also apply to Treatment Plans.
Historical archaeological studies at times are conducted for Caltrans by academic institutions, other agencies, or contracted private consultants. These studies should involve a Caltrans PQS PI-level historical archaeologist to ensure scopes of work, budgets, and deliverables are adequate considering the type and potential significance of the historic property as well as commensurate to the scope of the undertaking. In most districts, the historical archaeologist would assist the contract task order manager. If CCSO is participating in the administration of the historical archaeological study or providing peer review of reports, ideally CCSO personnel should participate in the fieldwork so that they have a better understanding of the nature of the resource involved.
Despite good faith efforts to identify historical archaeological properties, significant historical archaeological resources still may be discovered during construction. Consult Chapter 5 Section 5-10, and Exhibit 5.12. In addition, Exhibit 5.13 describes the procedure to use when reporting damage to cultural resources during construction.
Permits may be required before conducting historical archaeological studies on public or private lands. The permitting process is the same process used for prehistoric archaeological studies. Consult Chapter 5 Section 5-11 for guidance.
Prior to the distribution of the historical archaeological studies, reports and documents, there need to be three reviews:
- District or CCSO PQS, who is someone other than the author(s) of the documents, must peer review the Caltrans staff- and consultant-prepared draft documents.
- District PQS must review and approve the final document, under the terms of the Section 106 PA Stipulation XVI. For Caltrans-prepared documents, if the Caltrans PQS is certified at the appropriate PQS level, his or her signature on the final document as document preparer also signifies review for DEBC approval.
- DEBC must review and approve the final document.
Peer reviews are advisory and are considered to be part of the report preparation process. Peer reviewers may be identified in the acknowledgement section of the HRER and other archaeological documents or in a table of personnel working on the environmental studies. Peer review is separate from PQS approval of completed documents prior to submittal, which is required under the Section 106 PA. See Section 6-16.2 below.
In accordance with Caltrans Quality Assurance and Quality Control policy and the Section 106 PA Stipulation XVI, Caltrans PQS certified in the relevant discipline must peer review:
- Letter Reports
- Archaeological Study Reports
- Extended Phase I Proposals
- Extended Phase I Reports
- Archaeological Evaluation Proposals (formerly called Phase II proposals)
- Archaeological Evaluation Reports (formerly called Phase II reports)
- Data Recovery Plans
- Phase III Proposals
- Phase III Reports
- Historical Resources Evaluation Reports
Draft versions of curation agreements, monitoring plans, post review discovery plans and construction impact reports also may require peer review. Either district or CCSO PQS may conduct the peer review. If a DEBC requests peer review by another district or CCSO PQS, the DEBC submits the request to the appropriate DEBC or to the appropriate CCSO Branch Chief. Such reviews, whether in the district or in CCSO, will be completed within fifteen (15) working days of receipt of the request. However, longer review periods may be allowed at the discretion of the DEBC. Chapter 2 Section 2-5.5 discusses Caltrans internal review guidelines.
Likewise, CCSO PQS certified at the relevant level and discipline peer review the CCSO-prepared draft archaeological documents and HRERs. Upon approval, the CCSO Branch Chief or CCSO Office Chief transmits the CCSO-prepared documents to the requesting DEBC. Upon receipt, the DEBC has ten (10) working days to comment on the draft document, after which it is assumed to have met with the DEBC’s approval.
The process for resolving disagreements and differences of opinion regarding Caltrans or consultant-prepared findings is outlined in Chapter 2 Section 2-11.
Following peer review (whether by district or CCSO PQS), and any necessary revisions based on comments received, the report preparer signs the title page of the final archaeological document or HRER. If a Caltrans PQS has not prepared the document, then the responsible PQS indicates review and approval by signing the title page. The DEBC finally reviews and formally approves the document by signing the title page.
1988 Neither History nor Prehistory: the Questions that Count in Historical Archaeology. Historical Archaeology 22:7-12.