There are 24 US Post Offices in Douglas County serving a total of 77,207 residents equating to 3,217 residents per post office. It's estimated that approximately 123,231 packages are handled across the 24 county post offices annually. Douglas County is a county located in the U.S. state of Oregon. As of the 2010 census, the population was 107,667. The county seat is Roseburg. It is named after Stephen A. Douglas, an American politician who supported Oregon statehood. Douglas County comprises the Roseburg, OR Micropolitan Statistical Area.