The Elephant Back Loop Trailhead is temporarily closed to travel in Yellowstone National Park, Wyoming August 9, 2015. At least one grizzly bear attacked a hiker who was found dead and partially eaten in Yellowstone National Park in Wyoming, judging by wounds on his arms, park officials said on Saturday. A park ranger found the hiker's body on Friday in a popular back-country area near the Elephant Back Loop Trail near Yellowstone Lake in the middle of the park, park officials said. REUTERS/Jim Urquhart