Wild Horses Of Roosevelt National Park. The horse that is chancing that is Teton the leader of his band. I arrived when Teton was chasing many of the horses in the band. I had to hurry and set up my tripod and 500mm lens and was able to take a few shots and then had to carry my equipment around to finally get this shot. canon 7dii canon 500 mm lens shutter 2000 iso 1200 f5.6 exposed to the right one stop.