Union County is in Northeast New Mexico. Of the 33 counties in the Land of Enchantment, Union County is 15th in terms of its size (3,831 square miles). There is nearly 7,000 acres of residential land for sale in Union County, New Mexico, based on recent Land Network data. The combined market value of farms and ranches for sale here is almost $9 million. The average price of residential acreage for sale in Union County was $2 million. The county has a rural, farm-based economy. Browse all residential land and rural property for sale in New Mexico to find residential land and properties that suit your lifestyle needs, from existing residential homes and estates to land ready for future residential-property development.