Lake Ada Rose is a picturesque water reservoir located in Mendocino County, California, near the city of Willits. Built in 1964, this earth dam stands at a height of 50 feet and has a storage capacity of 138 acre-feet, serving primarily as a water supply source for the region. The dam is regulated by the California Department of Water Resources and undergoes regular inspections to ensure its structural integrity.

With a surface area of 7 acres and a drainage area of 0.7 square miles, Lake Ada Rose not only fulfills its primary purpose but also provides recreational opportunities for locals and visitors alike. The dam's hazard potential is considered high, although its condition assessment as of September 2017 was deemed satisfactory. Despite its age, the dam continues to play a vital role in water resource management in the area, showcasing the importance of maintaining and monitoring such critical infrastructure for the future.