Greenbelt Lake, formerly Greenbelt Reservoir, is in the Red River basin about four miles north of Clarendon in south central Donley County (at 35°00' N, 100°54' W). The reservoir, built at the convergence of Carrol and Kelly creeks with the Salt Fork of the Red River, is owned and operated by the Greenbelt Municipal and Industrial Water Authority to supply water for municipal and industrial use. Adams Construction Company started work on the 5,800-foot-long rolled earthfill dam on April 12, 1966; the dam was closed and water impoundment began on December 5. By 1968 the lake was on the verge of inundating the original townsite of Old Clarendon, prompting the removal of the old cemetery and other remnants of "Saints' Roost." The reservoir has a capacity of 59,110 acre-feet with a surface area of 1,990 acres at the service spillway elevation of 2,664 feet above mean sea level, and a capacity of 81,760 acre-feet with a surface area of 2,470 acres at the emergency spillway crest elevation of 2,674 feet above mean sea level. The drainage area above the dam is 288 square miles.