Mountain Passes

Caltrans District 10 manages three passes in the Central Sierra that are closed during winter and re-opened in the spring. These passes are:  Ebbetts Pass (State Route 4) in Alpine County, Sonora Pass (State Route 108) in Tuolumne County, and Monitor Pass (State Route 89) in Alpine County.

Caltrans District 10 ensures the timely seasonal closing and opening of these three passes by considering public and worker safety, public and economic interests, weather conditions, and existing snow levels as factors in determining the actual closing and opening dates from year to year. 

Although the locations for winter closures remain the same from year to year, the effort and time necessary for pass opening can vary greatly. The major factors that affect our efforts are the amount of accumulated snow, the frequency and duration of late season spring storms, springtime temperatures and winter damage to the roadway.

Crews typically begin removing snow from the roadway on the first Monday of April each year, and work seven days per week until each pass is free of snow and all roadway hazards before declaring them officially open for the spring and summer months.

 

Ebbetts Pass (State Route 4) in Alpine County

• The California Department of Transportation (Caltrans) officially reopened Ebbetts Pass (State Route 4) for the season on Wednesday, May 6, 2026. Favorable weather and subsequent road conditions were among the determining factors in the early decision to officially reopen the highway to motorists for the season. Caltrans top priority is ensuring the safety of the traveling public and our workers along with supporting the economic vitality of our local communities. We are pleased to reopen State Route 4 for the season without incident and to allow early public access for recreation activities along Ebbetts Pass.
• Each season, Caltrans District 10 maintenance crews work diligently to clear debris, remove snow, and make repairs so the highway with the goal of safely reopening the highway to motorists prior to Memorial Day. During the winter Ebbetts Pass is closed eastbound at the California State Parks Lake Alpine OHV SNO-Park, and westbound at the State Route 4/89 Junction. Caltrans winter pass closures are subject to weather and road conditions, for the real-time winter highway updates visit QuickMap.dot.ca.gov or download Caltrans QuickMap app to your mobile device.

Ebbetts Pass snow removal video: https://youtu.be/ydzaLdfKekA

 

Monitor Pass (State Route 89) in Alpine County

• The California Department of Transportation (Caltrans) officially reopened Monitor Pass (State Route 89) for the season on Thursday, March 5, 2026. Favorable weather and subsequent road conditions were among the determining factors in the early decision to officially reopen the highway to motorists for the season.
• Each season, Caltrans District 9 & 10 maintenance crews work diligently to clear debris, remove snow, and make repairs so the highway with the goal of safely reopening the highway to motorists prior to Memorial Day. During the winter Monitor Pass is closed eastbound at the State Route 4/89 Junction in Alpine County, and westbound at US-395 in Mono County. Caltrans winter pass closures are subject to weather and road conditions, for the real-time winter highway updates visit QuickMap.dot.ca.gov or download Caltrans QuickMap app to your mobile device.

 

Sonora Pass (State Route 108) in Tuolumne County

• The California Department of Transportation (Caltrans) officially reopened Sonora Pass (State Route 108) for the season on Thursday, April 30, 2026. Favorable weather and subsequent road conditions were among the determining factors in the early decision to officially reopen the highway to motorists for the season. Caltrans top priority is ensuring the safety of the traveling public and our workers along with supporting the economic vitality of our local communities. We are pleased to reopen State Route 108 for the season without incident and to allow early public access for recreation activities along Sonora Pass.
• Each season, Caltrans District 9 & 10 maintenance crews work diligently to clear debris, remove snow, and make repairs so the highway with the goal of safely reopening the highway to motorists prior to Memorial Day. During the winter Sonora Pass is closed eastbound at the California State Parks OHV SNO-Park, and westbound at the Marine Corps Training Facility. Caltrans winter pass closures are subject to weather and road conditions, for the real-time winter highway updates visit QuickMap.dot.ca.gov or download Caltrans QuickMap app to your mobile device.

Sonora Pass snow removal video: https://youtu.be/qd0nzDTx0II