Lake Sonoma is the largest lake in the county. In 1983 the United States Army Corps of Engineers completed the Warm Springs Dam and the lake was formed shortly thereafter. The compacted earth dam is 319 feet high and 3,000 feet long. The lake extends nine miles on Dry Creek and four miles on Warm Springs Creek. It has a capacity for 381,000 acre feet of water and serves as flood deterent, water storage and a wonderful site for water sports, fishing, hiking and camping.
The Milt Brandt Visitor Center and the Congressman Don Clausen Fish Hatchery are both open to the public all year long. The Visitor Center has a small but very interesting exhibit on the Pomo Indians of the area. The fish hatchery was built by the Corp of Engineers and is run by the California Department of Fish and Game. It's purpose is to enhance salmon and steelhead spawning grounds.