The creek's headwaters are in Mendocino County. The creek flows roughly southeast until reaches Lake Sonoma, which is formed by Warm Springs Dam. Several other creeks that used to merge with the creek now flow into the lake. Downstream of the dam, the creek continues flowing roughly southeast until its confluence with the Russian River.
Warm Springs Dam, a rolled-earth embankment dam completed in 1983, is about 14 miles (23 km) northwest of Healdsburg, California. It was built by the United States Army Corps of Engineers for flood control, irrigation, drinking water. The 381,000 acre-foot (470,000,000 m³) lake provides recreation, such as swimming, boating, waterskiing and fishing. Also, a hydroelectric plant at the dam produces electricity from the water released downstream. A minimum amount of flow in the creek must be maintained for fish migration.