Located in Missouri River Country Montana, 5,061-square-mile Valley County is one of the ten biggest counties in the Treasure State. There is 1,000 acres of residential land for sale in Valley County, Montana, based on recent Land Network data. The combined market value of farms and ranches for sale here is about $9 million. The average price of residential land for sale in Valley County was $2 million. The economy here is largely agricultural. Browse all residential land and rural property for sale in Montana 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.