Stapleton Airport Plans for building an airport at the Stapleton site began as early as 1929. The 123-acre Bluff Lake area was purchased by the Aviation Department from the Clayton Institute in 1970 and became part of the airport. The land became a “crash zone”, required at the end of all runways to shield the surrounding community from airplane activities. For the next fifty years, Bluff Lake remained undisturbed, surrounded by barbed wire fence and virtually ignored by Stapleton. During those fifty years, wildlife such as deer, red foxes, badgers, snakes, turtles, coyotes, owls, hawks, rabbits and a variety of waterfowl found their homes at Bluff Lake.
A New Era After Stapleton Airport closed on February 28, 1995, Bluff Lake Natural Area was established and protected under the terms of a settlement agreement between the City and County of Denver and the Sierra Club. The Sierra Club’s successful lawsuit against Denver's Department of Aviation was due to the inadequate retention ponds for ethanol glycol (the de-icing chemical for airplanes). During heavy rains, ethanol glycol would spill into Sand Creek and dramatically lower the dissolved oxygen levels, leading to fish kills. As part of the settlement, Denver agreed to preserve the Bluff Lake area and invest over three million dollars to enhance wildlife habitat, restore the banks of Sand Creek, build an interpretive trail system and construct open-air shelters.