John Day River (Major Population Group)
There are 5 extant summer run steelhead populations within the John Day River MPG: Lower Mainstem Tributaries, Middle Fork, North Fork, South Fork, and Upper Mainstem. The John Day River, which is completely within Oregon, flows west from the Blue Mountains and then north through a deeply carved, basaltic landscape and is the second-longest free-flowing river in the continental United States. There are no hydroelectric dams on the John Day River, and no releases of hatchery salmonids into lotic waters in the basin. In 1999 the National Marine Fisheries Service (NMFS) listed the Middle Columbia summer steelhead DPS, which includes the John Day River populations, as threatened under the ESA (U.S. Office of the Federal Register 1999). Adult abundance estimates have been made since 1959 using spawning ground surveys for the John Day River Basin as a whole, as well as the 5 populations within.