There was a total of around $314 million of farms, ranches, hunting land and other land for sale in Jefferson County recently on Land.com. The total size of all Jefferson County land for sale was around 200,000 acres. Jefferson County ranks 12th based on the total acres of land for sale among all the counties in the Beaver State. Madras featured the most land for sale. Jefferson County is Oregon's 21st biggest county (1,792 square miles). It's located in the Central Oregon region of the state.