The man worked with a company that runs urgent care clinics in the park, Yellowstone said in a statement today.
He had been reported missing by his coworkers that morning.
Preliminary results show the man was attacked by a grizzly bear, the park said. One adult female grizzly and at least one cub were likely involved.
"While the exact cause of death has not been determined, investigators have identified what appear to be defensive wounds on the victim’s forearms," Yellowstone said.
His body was found partially consumed and covered, the park said.
The man's identity has not yet been released.
Bear traps have been set in the area, Yellowstone said, adding that "if bears are trapped and identified as having been involved in the attack, they will be euthanized."
“We may not be able to conclusively determine the circumstances of this bear attack, but we will not risk public safety,” Yellowstone National Park Superintendent Dan Wenk said in a statement. “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.”
The investigation is ongoing, Yellowstone said, and the Elephant Back Loop Trail area is closed.