The valley in front of you was the site of the Wind Cave National Game Preserve, established in 1912 to reintroduce bison to the area. About 4,000 acres were enclosed to receive 20 bison from the New York Zoological Society and Yellowstone National Park, and Rocky Mountain elk and pronghorn antelope soon arrived. As the bison and elk herds increased, lands were added to the game preserve. In 1935 Congress combined the preserve with the national park, and the Civilian Conservation Corps moved the fences to the park boundary. Since then the park staff has had two missions: protect the prairie, forest, and wildlife, as well as the cave. In 1928, game warden A.P. Chambers said that propagating pronghorn antelope was difficult and required setting aside large tracts of land because they would not thrive in confinement.