A hiker was found dead Friday afternoon on a trail at Yellowstone National Park. The man was found on the Elephant Back Loop Trail, and an investigation is now underway to determine the cause of death, according to the National Park Service.

The man, who worked at Yellowstone, was found around noon on Friday after co-workers reported him missing, according ABC News. 

Yellowstone spokeswoman Julena Campbell said that a conclusive cause of death has yet to be determined. 

She went on to say, however, that rangers investigating the incident have found signs of grizzly bear activity in the area, like bear scat, fur and day beds (patches of depressed grass), where one or more bears might have rested during the day. 

The name of the victim has not yet been released. 

Park officials continue to advocate safety to it's 3.5 million annual visitors and warn them about the dangers associated with hiking Yellowstone's 2.2 million acres.
 
While fatal bear attacks are uncommon, park officials urge visitors to stay on designated trails, leave an itinerary with others, hike in groups of three or more, make noise on the trail and carry bear spray, Yahoo! News reported. 

The Elephant Back Loop Trail and immediate areas are currently closed while the investigation ensues.