The peregrine falcon, a magnificent raptor that soars through the air and dives at amazing speeds, began to decline in numbers in the 1950s and 60s. Several factors contributed to the decline, most significant was thought to be the use of DDT, a chemical pesticide that accumulated in the tissues of birds of prey and caused thinning of eggshells so that the eggs often broke during incubation. Both the American peregrine falcon, Falco peregrinus anatum, and the arctic peregrine falcon, Falco peregrinus tundrius, were placed on the endangered species list in the 1970s.

With the listing of peregrines as endangered, many parks responded enthusiastically by participating in cooperative efforts to restore the falcons. The banning of the pesticide DDT in 1972 and the reintroduction of captive-reared chicks to former breeding sites enabled peregrine populations to recover sufficiently for the arctic peregrine falcon to be delisted in 1994 and the American peregrine falcon to be delisted in 1999.

Today peregrine falcons are likely present in over 159 parks. Peregrine falcons are found in large parks such as Yellowstone and also in urban parks such as National Capital Parks East in Washington, D. C.