Long Lake, located in Graeagle, California, is a privately owned reservoir on Gray Eagle Creek with a primary purpose of water supply for irrigation and other uses. The dam, completed in 1938, is a rockfill structure standing at 12 feet high and holding a storage capacity of 1478 acre-feet. With a surface area of 141 acres and a drainage area of 1.13 square miles, Long Lake provides essential water resources for the surrounding area.

Managed by the California Department of Water Resources (DWR) under the Safety of Dams program, Long Lake is regulated, permitted, inspected, and enforced to ensure its structural integrity and safety. The dam is classified as having a significant hazard potential but is currently assessed as being in satisfactory condition as of September 2017. The last inspection in October 2020 indicated that the dam meets guidelines and emergency preparedness measures are in place.

Water resource and climate enthusiasts visiting Long Lake can appreciate the engineering feat of the rockfill dam, the serene beauty of the reservoir, and the vital role it plays in providing water for irrigation and other needs in the Plumas County area. As a well-regulated and maintained water source, Long Lake is a testament to the importance of sustainable water management practices in the face of changing environmental conditions.