Gray Reef is a federal-owned irrigation dam located in Natrona County, Wyoming, along the North Platte River. Built in 1961 by designer R M Sensintaffar, this earth dam stands at a height of 38 feet, with a hydraulic height of 25 feet and a structural height of 36 feet. It has a length of 650 feet and a storage capacity of 1804 acre-feet, serving the primary purpose of irrigation for the surrounding area. Managed by the Bureau of Reclamation, Gray Reef is regulated, permitted, inspected, and enforced by state agencies to ensure its safety and functionality.

With a low hazard potential and a very high risk assessment rating, Gray Reef has a controlled spillway with a width of 100 feet and two Tainter (radial) outlet gates. The dam is situated in a drainage area of 11,000 square miles, with a maximum discharge of 20,700 cubic feet per second. Although the condition assessment is not available, regular inspections occur every three years to maintain its integrity. Despite its age, Gray Reef continues to play a crucial role in providing water resources for irrigation purposes in the region, showcasing the importance of sustainable water management practices in the face of changing climate conditions.