At top conservation pool, the lake at Red Willow Reservoir covers 1,628 acres of the nearly 6,000 acres managed for public recreation and wildlife. The dam on Red Willow Creek is a zoned, earth-filled structure, 126 feet high and 3,159 feet long. Completed in 1962, it measures 30 feet thick at the top with a maximum base of 820 feet. Its waters provide primary or supplemental irrigation for 28,524 acres of land.