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 foothill, 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.