Humboldt County Map shows the county’s location, the county seat, neighboring counties, the state capital, and many more. Humboldt County is located in north-central Nevada. Its total area is 9,658 sq mi (25,010 sq km), of which 9,641 sq mi (24,970 sq km) is land area and 17 sq mi (40 sq km) is water area. Winnemucca is the county seat and also the largest city.