Land for sale in Yellowstone County recently totaled around $398 million and nearly 100,000 acres. Based on the combined acreage of land and rural property for sale here, Yellowstone County has the most land for sale of all counties in Big Sky Country. There were three properties listed as sold in Yellowstone County through the Land Network Comparable Sales Program. This represented a total value of $2,925,000. Billings featured the most land for sale. Yellowstone County is the 23rd largest county (2,648 square miles) in Montana. It's located in the Southeast Montana region of the state.