Hart Mountain National Antelope Refuge is a National Wildlife Refuge on Hart Mountain in southeastern Oregon, which protects more than 422 square miles (1,090 km2) and more than 300 species of wildlife, including pronghorn, bighorn sheep, mule deer, sage grouse, and Great Basin redband trout. The refuge, created in 1936 as a range for remnant herds of pronghorn, spans habitats ranging from high desert to shallow playa lakes, and is among the largest wildlife habitats containing no domestic livestock.