At the time of its completion in 1925, the Tieton Dam was the highest earthfill dam in the world. "Two of the foremost engineers in Western water development, Frank Crowe and Frank Weymouth, were involved in its construction." [CH2M Hill 1984: 17]. Several innovative construction methods involving the use of tunnels and shafts were applied to excavate the core wall, for deep excavations and unconsolidated rock surfaces made open trenching an impossibility. An important unit of the Bureau of Reclamation's Yakima Project, the Tieton Division is a series of storage dams, including the Tieton Dam, and complex conveyance systems that opened large areas of dry shrubland to irrigation and permanent settlement. The success of this project spurred development of irrigated agriculture throughout central and eastern Washington. The Tieton Dam was determined to be eligible for listing in the National Register of Historic Places in 1983.
Rimrock Lake is a lake along the course of the Tieton River, in Yakima County, Washington state, US.
The lake is used as a storage reservoir for the Yakima Project, an irrigation project run by the United States Bureau of Reclamation. An impoundment of the Tieton River, Rimrock Lake's capacity and discharge is controlled by Tieton Dam, a 319-foot (97 m) high structure built in 1925. Rimrock Lake's active capacity is 198,000 acre-feet (244,000,000 m3).[1]
Upstream from the lake, the Tieton River is impounded by Clear Creek Dam, another element of the Yakima Project. About 8 miles (13 km) downstream from Rimrock Lake the Tieton River is tapped by the Tieton Diversion Dam, supplying water to the Tieton Main Canal. The canal supplies irrigation water to the Tieton Division of the Yakima Project, with excess and agricultural runoff draining into Ahtanum Creek, west of Yakima.[1]
Near the lakes are the communities of Rimrock and Silver Beach.