Though the exact cause of death has not been determined, investigators identified what appear to be defensive wounds on the victim's forearms, Yellowstone National Park said in a statement Saturday. A forensic autopsy is scheduled for later Monday.
The victim, 63-year-old Lance Crosby, was a long-term seasonal employee of Medcor, a company that operates three urgent-care clinics in Yellowstone. An experienced hiker, he had worked and lived in Yellowstone for five seasons, the statement said.
"We are deeply saddened by this tragedy and our hearts go out to the family and friends of the victim as they work to cope with the loss of someone who loved Yellowstone so very much," Yellowstone National Park Superintendent Dan Wenk said.
Crosby was reported missing Friday morning when he did not report for work. A park ranger found his body in a popular off-trail area less than a mile from Elephant Back Loop Trail, an area he was known to frequent. His body was partially eaten and covered, the statement said.
Based on partial tracks found at the scene, it appears that an adult female grizzly and at least one cub were present and probably were involved in the incident near Yellowstone Lake, the statement said.
Wildlife biologists set bear traps in the area on Friday evening and captured an adult female grizzly. The bear will be euthanized if it's identified through DNA as the animal responsible in the attack.
"The decision to euthanize a bear is one that we do not take lightly. As park managers, we are constantly working to strike a balance between the preservation of park resources and the safety of our park visitors and employees," Wenk said.
"Our decision is based on the totality of the circumstances in this unfortunate event. Yellowstone has had a grizzly bear management program since 1983. The primary goals of this program are to minimize bear-human interactions, prevent human-caused displacement of bears from prime food sources, and to decrease the risk of bear-caused human injuries."
The Elephant Back Loop Trail and immediate area are closed until further notice. Signs are posted, and maps of the closure area are available at park visitor centers.
The grizzly bear population in the Greater Yellowstone Ecosystem was estimated to be to between 674 and 839 in 2014, according to the National Park Service. Park regulations state that people must stay 100 yards away from bears.
Deadly encounters between bears and humans are rare in Yellowstone. From 1872 to 2011, black and grizzly bears have killed seven people in the park, according to its website
This is the first fatal human-bear encounter in Yellowstone in 2015, park spokeswoman Amy Bartlett said. There have been five bison gorings, none of which has been fatal.