A combined almost 200,000 acres were listed for sale in Oregon's Jefferson County recently; the value of all Jefferson County land and rural real estate for sale was around $332 million. Jefferson County ranks 12th in Oregon based on the total acres of land for sale among the 36 counties in the Union State. Madras had the most land for sale. Jefferson County is Oregon's 21st largest county (1,792 square miles). It's located in the Central Oregon region of the state.