The Black Hills, a dominant feature on the prairie landscape and surrounded by native prairies, now support Wyoming's largest population of white-tailed deer and wild turkeys, along with common pronghorn antelope, mule deer, red squirrels, and sharp-tailed grouse. Journal excerpts from Colonel George Custer's 1874 expedition indicate that grizzly bear, elk, white-tailed deer, mule deer, and beaver were common there, antelope were numerous, buffalo skulls dotted the surrounding plains, and timber wolves were the most common large predator in the Hills, while coyotes were rare where their ranges overlapped with wolves but abundant on the surrounding plains. Turkeys were introduced to the Black Hills in the 1930's. At the turn of the century, professional hunters supplying meat, furs, and feathers to eastern markets severely depleted all game species, while rapid settlement converted many areas into irrigated cropland. Wildlife began to rebound during the early to mid-1900's through protective wildlife laws, strict law enforcement, game transplants, and the participation of cooperative landowners.