The canyon and its rims are home to a variety of wildlife, from the chipmunks and ground squirrels to weasels, badgers, marmonts, and black bear. Infrequently bobcat and cougers are sighted, and at night , coyotes may be heard. If you come across trees that have been gnawed on, you will have found evidence that porcupines are thereabouts, for the bark of pinyon pine is one of the favorite foods of these nocturnal animals. The Gambel oak and serviceberry that cover most of the Gunnison Uplift provide a good habitat for towees, western tangers, pinion and scrub jays, and black-billed magpies. The cliffs are home to white-throated swifts, violet-green swallows, golden eagles, turkey vultures, and red-tailed hawks, who all take advantage of the updrafts for soaring. The canyon is one of the last shelters in Colorado for the endangered peregrine falcon. Through a home to wildlife, the canyon has been . a mighty barrier to human beings. Archeological evidence indicates that prehistoric man, and later the Utes, used only the canyon rims, never living in the gorge. The first white men to see the great chasm actually were members of the Hayden Expedition in 1873-74. It appears that the Spaniards, including the famed Dominguez-Escalante Expedition in 1776, all missed the canyon as they came over the Uncompahgre Plateau and into the Uncompahgre Valley on various journey's of exploration. Even the group led by Capt. John W. Gunnison, whose name has become permanently attached to the river, bypassed the gorge itself in its search for a river crossing. The Hayden Expedition and later surveying parties for the Denver & Rio Grande Railroad all pronounced the Black Canyon "inaccessible".