Marin (Marin was probably the name of the chief of the local Miwok tribe, who fiercely resisted the Spanish invasion) is one of the 58 counties in the state of California. It was created in 1850, making it one of the original counties of the state. As of the 2010 census, the population was 252,409, up from 247,289 in 2000. The county seat is San Rafael. The largest city (in size) is Novato.
The county has 828.2 square miles (2,145.0 km2) of area, including 519.80 square miles (1,346.3 km2) of land. Marin only has one bordering county, Sonoma on the north and northeast. But it has bridge connections to San Francisco County to the south and Contra Costa County to the east.
Marin is one of the nine traditional Bay Area counties.