Mahon Reservoir, located in Harney County, Oregon, serves as a vital irrigation source for the surrounding area. Built in 1904, this Earth dam stands at a height of 25 feet and has a storage capacity of 3456 acre-feet. The reservoir is fed by Camp Creek and the South Fork Malheur River, with a drainage area of 30.4 square miles and a surface area of 12.1 acres.

With a low hazard potential and a moderate risk assessment rating, Mahon Reservoir is crucial for agricultural activities in the region. The dam has not been rated for its condition, but it is regularly inspected and maintained by the Oregon Water Resources Department. The spillway type is listed as uncontrolled, with a maximum discharge capacity of 90 cubic feet per second.

Despite its age, Mahon Reservoir continues to play a key role in water resource management in the area, providing reliable irrigation water for agricultural purposes. As a privately owned structure, it is subject to state regulations and inspections to ensure its safety and functionality. With its strategic location and historical significance, Mahon Reservoir stands as a testament to the importance of sustainable water management practices in the face of changing climate patterns.