CTUIR Fish Habitat Restoration in the Walla Walla River Basin

The Walla Walla River flows from the northern Blue Mountains into the Columbia River near Wallula, Washington. The river originates at an elevation of nearly 6,500 feet and the Walla Walla watershed covers an area of 1,758 square miles. The majority of the basin (~75%) is located in southeastern Washington with the remainder located in northeastern Oregon.

Historically, the Walla Walla basin supported healthy populations of steelhead, Bull Trout, Chinook Salmon, freshwater mussels, and lamprey. Currently, two fish species listed as threatened under the Endangered Species Act are present in the basin: Middle Columbia River steelhead (anadromous Oncorhynchus mykiss) and Bull Trout (Salvenlinus confluentus). The last significant run of spring Chinook salmon (Oncorhynchus tshawytscha) in the basin occurred in 1925 and declined until extirpated in the 1950’s.