Wallowa County is a county located in the U.S. state of Oregon. As of the 2010 census, the population was 7,008, making it the fourth-least populous county in Oregon. Its county seat is Enterprise. According to Oregon Geographic Names, the origins of the county's name are uncertain, with the most likely explanation being that it is derived from the Nez Perce term for a structure of stakes (a weir) used in fishing. An alternative explanation is that Wallowa is derived from a Nez Perce word for "winding water". The journals of Lewis and Clark Expedition record the name of the Wallowa River as Wil-le-wah.