Rimrock Lake which is part of the Yakima Project was formed by the construction of Tieton Dam on the Tieton River. Bumping, Rimrock, and Clear Lakes are in Wenatchee National Forest. The rugged mountain terrain, surrounded by coniferous forest, creates magnificient scenic settings. The lake, along with Clear Lake, provides 2,790 water-surface acres. Available species include rainbow trout and kokanee. Reservoir levels.