Administration
For administrative purposes, Caltrans has divided the state of California into 12 districts supervised by district offices. Most districts cover multiple counties; District 12 (Orange County) is the only district with one county. The largest districts by population are District 4 (San Francisco Bay Area) and District 7 (Los Angeles and Ventura counties). Like most state agencies, Caltrans maintains its headquarters in Sacramento, which is covered by District 3.
Read more about this topic: California Department Of Transportation