About Caltrans District 10

District 10 is a geographically diverse district located in the northern San Joaquin Valley that encompasses 29 cities, eight counties, three urban counties on the valley floor, five rural counties in the foothills, and a mountain region of the Central Sierra. The counties include Alpine, Amador, Calaveras, Mariposa, Merced, San Joaquin, Stanislaus, and Tuolumne. The District covers: 3,547 lane miles, 854 bridges, 715 acres of landscape areas, roughly 11,000 culverts, 1,395 highway center-line miles open to pedestrians and bicycles, four Sierra snow passes, three rest areas, 24 maintenance stations, 19 airports, the Port of Stockton, and numerous transit and rail authorities.

The major urban areas located within the boundaries of District 10 that include the cities of Stockton, Modesto, and Merced has a combined population of approximately 1.5 million people. The District borders the East Bay Area and continues to experience increased levels of congestion due to heavy commuter traffic through I-580, the Altamont Pass, and other routes.

The five mountain counties also continue to experience a vast amount of growth.  This development is primarily focused next to the existing foothill communities. Two of the District’s mountain counties, Mariposa and Tuolumne, which border Yosemite National Park. The District has been very active in communication and inter-regional issues concerning Yosemite National Park access and the development of the Yosemite Area Regional Transportation Systems, YARTS.

Caltrans Mission is to provide a safe and reliable transportation network that serves all people and respects the environment. Please see the contact information below to help us help you with your request or inquiry. Thank you.

Contact Caltrans District 10

Grace B. Magsayo
Acting District Director
(209) 942-6192



Ramamohan Bommavaram
Safe System Lead
(209) 693-3995


Cristin Hallissy
Acting Deputy District Director
Environmental & Right of Way
(209) 693-3741



Grace B. Magsayo
Deputy District Director
Program Project Management and Asset Management
(209) 942-6192



Eric Mather
Deputy District Director
(209) 948-7896



Tanya Sanguinetti
Deputy District Director
(209) 986-6837



Mark Samuelson (Acting)
Deputy District Director
Planning, Local Assistance and Environmental
(916) 651-8899



Caroline Reyes
Deputy District Director
Project Development and Construction
(559) 974-2820



Sam Sherman
D10 Clean CA
Program Coordinator
(209) 948-7889



Duper Tong
Deputy District Director
Traffic Operations
(209) 986-9871


Main Line

For general assistance and to direct inquiries (209) 948-7543


Customer Service Requests

For customer service to report road conditions and initiate Maintenance Service Requests please visit: https://csr.dot.ca.gov/ or call (209) 948-7977


Public and Legislative Affairs

For all Public, Legislative, and Media inquiries (209) 986-0859


District 10 Current Projects

Project information, Project Scope, Environmental Documents and Public Hearing Notices by county



Caltrans Quickmap

Current Road Conditions, Fast/Slow Traffic Scale, Lane Closures, Full Closures, CHP Incident Warnings, CHIN Message Warnings, Chain Controls, Snowplow Operations and more http://quickmap.dot.ca.gov/


Encroachment Permits

Arrange for any tower, pole, line, pipe, fence, billboard, structure, object, or special event within the State highway right of ways (209) 948-7891


Local Assistance

State and Federal Program oversight and assistance for cities, counties, and regional agencies for the purpose of improving their transportation infrastructure (209) 948-3689


D10 Encampment Coordinator

Guidance on response efforts of the Governor's Executive Order N-32-20 Homelessness and Encampment initiative. Plans, develops and implements policies, procedures and services involving encampments (209) 986-9428


Planning Metropolitan

Guides and advocates for California's regional transportation planning process and ensures federal and State legislation, policies, and priorities are met (209) 941-1921


D10 Broadband Project/Program Coordinator

Guidance on Federal and State policy, and District Directives on Broadband deployment for projects within State right-of-way (209) 351-4432


District 10 Public Claims

Mail to: District 10 Claims - Stockton, PO Box 2048, Stockton, CA 95201 or call (209) 948-7864


Construction Claims and Disputes

Resolve differences on construction projects including fair time extensions, fair payment for added and unanticipated work, claims and more (209) 639-4453


Small Business

Contractor and Supplier Certification Assistance, Projects opening for bids, and Contractor Training (209) 610-7977



Provides options for individuals, organizations, or businesses to help maintain sections of Caltrans roadsides (209) 948-7462


Personnel Help Desk

General information on applying for State employment (209) 948-7924


Traffic Operations

Mobility and travel, commercial vehicle operation, and traffic safety (209) 948-3995


Program, Project, and Asset Management

Responsible for the District 10 portfolio of transportation improvement projects (209) 948-7428


D10 Contact Us Jan 2024