The Oregon high desert is a region of the U.S. state of Oregon located east of the Cascade Range and south of the Blue Mountains, in the central and eastern parts of the state. Divided into a southern region and a northern region, the desert covers most of five Oregon counties and averages 4,000 feet (1,200 m) above sea level. The southwest region is part of the Great Basin and the southeast is the lower Owyhee River watershed. The northern region is part of the Columbia Plateau, where higher levels of rainfall allow the largest industry on private land to be the cultivation of alfalfa and hay. Public land within the region is owned primarily by the Bureau of Land Management, which manages more than 30,000 square miles (78,000 km2) including five rivers designated as Wild and Scenic.