Tieton Dam

Tieton Dam sits at 2,936 feet along the byway between Kosmos Road near Morton and SR 410 near Naches. The dam is an earth and concrete structure on the Tieton River, in operation since 1925, and forms Rimrock Lake, which holds a total capacity of 203,600 acre-feet and a normal operating capacity of 198,000 acre-feet for agricultural irrigation. It is part of the Yakima Project, and the Southern California Public Power Agency installed two 7 megawatt generators here in a project started in 2010, sending power over the Pacific DC Intertie to Burbank Water and Power and Glendale Water and Power in the Los Angeles area. Upstream, Clear Creek Dam impounds the river before it reaches Tieton Dam, and about 8 miles downstream the river is tapped for the Tieton Main Canal. From the overlook, Goose Egg Mountain is visible to the east at 1.4 miles, rising to 4,513 feet. The terrain drops 10 feet within 600 meters of the site. Yakima lies 30.2 miles east, Ellensburg 37.1 miles northeast, and Kittitas 41.4 miles northeast. The previous stop along the byway is the Clear Creek Overlook Interpretive Site.