Reedsport is a coastal town in northwest Douglas County, Oregon, United States. As of the 2020 census, the population was 4,310. It is locateā¦Reedsport is a coastal town in northwest Douglas County, Oregon, United States. As of the 2020 census, the population was 4,310. It is located about 73 miles northwest of Roseburg, the county seat. Reedsport was established on the estuary of the Umpqua River on January 7, 1852. It was named for a local settler, Alfred W. Reed, who founded the city in 1912. The post office was established July 17, 1912.