Marin County

Administrative district of northwestern California; area 1,355 sq km/523 sq mi, population (1990) 230,100. Marin County lies largely on the Marin Peninsula, between San Pablo and San Francisco bays and the Pacific Ocean, and on the far side of the Golden Gate from San Francisco. The county seat is at San Rafael.

Many of San Francisco's most affluent neighbourhoods lie among the woods, hills, and beaches of Marin County. These include Sausalito, Mill Valley, Tiburon, and Corte Madera. Novato and San Rafael are the largest cities. Mount Tamalpais, Muir Woods National Monument, Point Reyes National Seashore, and San Quentin Prison are situated in the county. Economic activity centres on tourism, some agriculture and light industry, and the extraction of sand, clay, and stone.