Diemer Reservoir, located in Pitkin County, Colorado, is a federal-owned Earth dam constructed in 1929 by the USDA Forest Service with a primary purpose of serving as a Fish and Wildlife Pond. With a dam height of 13 feet and a hydraulic height of 18 feet, this reservoir has a storage capacity of 100 acre-feet and a normal storage level of 60 acre-feet. The reservoir is situated along the tributary North Fork Frying Pan River, providing a crucial habitat for various aquatic species in the region.

Despite being categorized as having a low hazard potential, Diemer Reservoir is subject to moderate risk (rated 3) due to its condition assessment being marked as "Not Rated." The reservoir features an uncontrolled spillway with a width of 8 feet and outlet gates that are also uncontrolled. The last inspection was conducted in July 2017, with a scheduled inspection frequency of every 10 years. While the risk management measures and emergency preparedness plans are not currently assessed or updated, the reservoir continues to play a vital role in supporting fish and wildlife populations in the area.

Water resource and climate enthusiasts are drawn to Diemer Reservoir for its historical significance as an early 20th-century water management structure, as well as its ecological importance as a habitat for local flora and fauna. As part of the USDA Forest Service's portfolio of water conservation projects, this reservoir stands as a testament to the agency's commitment to preserving natural resources while balancing the needs of various stakeholders. With its serene location in the Colorado wilderness, Diemer Reservoir serves as a reminder of the delicate balance between water resource management and environmental conservation in the face of a changing climate.