The term 'Yellowstone Deer' refers to the species of ELK (Cervus canadensis) that inhabit Yellowstone National Park in the United States. The ELK is one of the most iconic animals of the park and is a popular game animal for hunters. They are the largest species of deer in North America, with males weighing up to 700 pounds. ELK are known for their large antlers, which are shed and regrown each year.