Oak Valley is an unincorporated community in Elk County, Kansas, United States. It is located along U.S. Route 160 highway between Longton and Elk City. History A post office was opened at Oak Valley in 1875, and remained in operation until it was discontinued in 1954. Oak Valley was founded in 1879, when a settler built the first residential structure. References Further reading External links Elk County maps: Current, Historic, KDOT Unincorporated communities in Elk County, Kansas Unincorporated communities in Kansas