Land for sale in Los Alamos County, New Mexico, recently totaled around $17 million and almost 1,000 acres. Los Alamos County ranks 29th in the Land of Enchantment for the total number of acres of land currently advertised for sale. Of all locations in Los Alamos County with farms, ranches, hunting land and other land for sale, Los Alamos had the most land for sale. Los Alamos County is the 33rd largest county (109 square miles) in New Mexico. It's located in the North Central New Mexico region of New Mexico.