Mono County /ˈmoʊnoʊ/(MOH-noh) is a county in the U.S. state of California. As of the 2010 census, the population was 14,202, making it the fifth-least populous county in California. The county seat is Bridgeport. The county is located east of the Sierra Nevada between Yosemite National Park and Nevada. Mono County was founded in 1861.