Dworshak National Fish Hatchery is a mitigation hatchery located on the Clearwater River within the Nez Perce Reservation near Orofino, in north-central Idaho. It was constructed in 1969 by the Army Corps of Engineers, and is co-managed by the U.S. Fish and Wildlife Service and the Nez Perce Tribe. The hatchery is one of the largest combination producers of anadromous (migratory) fish in the world. These fish make a 1000 mile round trip to the ocean and back to spawn in the Clearwater River. The Dworshak Dam blocks access to the historical spawning areas on the North Fork-Clearwater River for the steelhead, and it is too high for a fish ladder.