Churchill County Nevada Map shows the county’s location, the county seat, neighbouring counties, the state capital, etc. Churchill County is located in the west part of Nevada. Its total area is 5,024 sq mi (13,010 sq km), where 4,930 sq mi (12,800 sq km) land area and 94 sq mi (240 sq km) is water area. Fallon is the county seat and also the largest city.