There was a combined nearly $47 million of farms and ranches for sale in San Juan County, Utah, recently on Land.com. The total acreage of all San Juan County land for sale was nearly 5,000 acres. San Juan County ranks 21st out of 29 counties in Utah for the combined amount of land currently advertised for sale. Among cities in San Juan County with farms, ranches, and rural real estate for sale, Moab featured the most land for sale. Mining and mineral extraction-related services are the main economic drivers in this part of Utah. San Juan County is the largest county in Utah (7,933 square miles). It's located in the East Utah region of the state.