On January 7, 1852, the territorial legislature created Douglas County from the eastern part of Umpqua county. In 1853 Umpqua County lost its northern part to Lane County. Finally, in 1862, the remainder of Umpqua county was incorporated into Douglas County.
Some accounts state this was because of decreased population following the end of the local gold rush; other accounts state that politics caused the end of this Oregon County.