Land for sale in Garfield County recently totaled around $10 million and around 9,000 acres. Garfield County ranks 45th in Big Sky Country for the total acreage of land currently advertised for sale. Mosby had the most land for sale. Garfield County has a large agricultural economy, with 297 farms recorded in the county during the latest U.S. Census. Farming activities in Garfield County generate annual revenues of $4 million, the majority of which comes from livestock products. Garfield County is one of the ten biggest counties in Montana (4,849 square miles). It's located in the Missouri River Country Montana region of the state.