The U.S. Congress had approved the building of a dam near Pacific, Missouri in 1938 to help control the flooding of the Meramec River, which had devastated the lower river basin in 1915 and 1944. The U.S. Army Corps of Engineers proposed relocating the dam upstream at Meramec State Park in 1943. Riley had spoken in favor of the dam in 1949, believing this would bring additional tourism to the area. An iteration of this plan was authorized by Congress in 1967 as the Meramec Park Lake Project, which included the dam at Meramec as well as 30 others along the Meramec, Bourbeuse, and Big rivers.