Land for sale in New Mexico's Sierra County recently totaled approximately $29 million and approximately 100,000 acres. Sierra County ranks 22nd in New Mexico for the total number of acres of land currently advertised for sale. Elephant Butte featured the most land for sale. From an economic perspective, government and state-level services contribute most to Sierra County's overall GDP. Sierra County is New Mexico's 12th biggest county (4,238 square miles). It's located in the Southwest New Mexico region of New Mexico.