Washington State Route 17 Coulee City–Brewster branch of PSH 10 was codified in 1931 as a branch of State Road 10 and re-codified in 1937, during the creation of the primary and secondary state highways; however, the highway was not built between Sims Corner and Bridgeport until the 1950s. The Soap Lake–Coulee City branch of PSH 7 was established in 1937 to serve as an alternate route to SSH 2F, avoiding the Grand Coulee Dam. In 1951, the PSH 10 branch between Bridgeport and Brewster was moved north of the Columbia River via the newly built Columbia River Bridge on the present route of
Grand Coulee Dam Coulee Dam flooded over 21,000 acres (85 km) of prime bottom land where Native Americans had been living and hunting for thousands of years, forcing the relocation of settlements and graveyards. The Office of Indian Affairs negotiated with the United States Bureau of Reclamation on behalf of tribes who were concerned about the flooding of their grave sites. The Acquisition of Indian Lands for Grand Coulee Dam, 54 Stat.703 Act of June 20, 1940 allowed the Secretary of the Interior to remove human remains to new Native American grave sites. The burial relocation project started in September 1939. Human remains