Mono is one of the 58 counties in the state of California. It was created in 1861 from parts of Calaveras, Fresno, and Mariposa counties. As of the 2010 census, the population was 14,202, up from 12,853 in 2000. The county seat is Bridgeport and the largest city is Mammoth Lakes.
The county covers 3,131.80 square miles (8,111.3 km2), of which 3,044.40 square miles (7,885.0 km2) is land. It is bordered by Inyo County, California on the south, Fresno and Madera counties to the southwest, Tuolumne County to the west, Alpine County on the northwest, Douglas County, Nevada on the north, Lyon County, Nevada on the northeast, Mineral County, Nevada on the east and Esmeralda County, Nevada on the southeast.