Upper Letts is a federal dam located in Stonyford, California, along Letts Creek. Built in 1958 by the USDA Forest Service, this earth dam stands at 21 feet high with a hydraulic height of 26 feet, serving primarily for recreation purposes. With a storage capacity of 319 acre-feet, Upper Letts offers a serene environment for water resource and climate enthusiasts to enjoy various water-related activities.

Despite its small drainage area and uncontrolled spillway type, Upper Letts poses a high hazard potential with a moderate risk assessment rating. Currently, the dam's condition remains unrated, with the last inspection conducted in June 2014 by the Forest Service. While emergency preparedness measures have not been specified, the dam's risk management strategies and inundation maps readiness are unknown, highlighting the need for proactive monitoring and maintenance to ensure the safety of the surrounding community and recreational users.

As part of the San Francisco District, Upper Letts is closely regulated and operated by the Forest Service, emphasizing the importance of continued oversight and adherence to safety guidelines. With its picturesque location and potential risks, Upper Letts serves as a reminder of the delicate balance between utilizing water resources for recreation while safeguarding against potential hazards in the face of changing climate patterns and environmental conditions.