There was a combined around $238 million of farms and ranches for sale in Montrose County recently on Land.com. The total size of all Montrose County farms, ranches, hunting land and other land for sale was around 100,000 acres. Montrose County ranks 15th in the Rocky Mountain State for the combined amount of land currently advertised for sale. Montrose had the most land for sale. Montrose County is the 16th biggest county (2,242 square miles) in Colorado. It's located in the Southwest Colorado region of the state.