There was a total of nearly $28 million of farms, ranches, hunting land and other land for sale in Roosevelt County, Montana, recently on Land.com. The total size of all Roosevelt County farms, ranches, hunting land and other land for sale was nearly 100,000 acres. Roosevelt County ranks 39th in Montana for the combined amount of land currently advertised for sale. Of all land and rural real estate for sale in Roosevelt County, Oswego featured the most land for sale. Roosevelt County is Montana's 29th biggest county (2,369 square miles). It's located in the Missouri River Country Montana region of the state.