Farmington is a city in San Juan County in the U.S. state of New Mexico. As of the 2013 population estimate from the United States Census Bureau the city had a total population of 45,426 people. Farmington makes up one of the four Metropolitan Statistical Areas in New Mexico. The U.S. Census Bureau's population estimate in 2011 for Farmington was about 45,256.Farmington is located at the junction of the San Juan River, the Animas River, and the La Plata River, and is located on the Colorado Plateau. Farmington is the largest city of San Juan County, one of the geographically largest counties in the United States covering 5,538 square miles. The county seat and the other city in San Juan County is Aztec. Farmington serves as the commercial hub for most of northwestern New Mexico and the Four Corners region of four states. Farmington lies at or near the junction of three important highways: U.S. Highway 550, U.S. Highway 64, and New Mexico Highway 371.