A man was killed while hiking in Yellowstone National Park on Wednesday after he encountered a female grizzly bear and her cubs.
The mauling occurred just a mile and-a-half into the Wapiti Lake trail. According to park authorities, a group of nearby hikers heard the victim's wife crying out for help and phoned the rangers for assistance.
According to a National Park Service statement, the couple had accidentally surprised the mother grizzly and her cubs and, in an attempt to defend a perceived threat to her cubs, the bear attacked and fatally wounded the man.
Park officials said on Wednesday that the bear involved had not been captured and they did not immediately have enough information to determine what, if any, measures they might take.
Park spokeswoman Linda Miller added that initial information indicated that the mother bear behaved normally in defending her cubs and would not be killed as a result. This is in tune with the park's policies in the past, though bears who have had repeated run-ins with park visitors are often relocated.
If we have an aggressive bear that continually poses a threat to human safety, then we work to remove it from the ecosystem, Yellowstone spokesman Al Nash said, adding he did not know if this grizzly had any previous human encounters.
According to park records, Wednesday's incident was the first bear-caused human death in the park since 1986. While this may be true, a mother grizzly killed one man and injured two others in an unusual nighttime attack on sleeping campers just outside of Yellowstone in Montana last July. That bear was later killed because his actions were seen as predatory and unprovoked.
In general, attacks by bears are extremely rare, and not one bear had been reported along the Wapiti Lake trail this year.
Officials advised park visitors to stay on designated trails, hike in groups of three or more people, and to be alert for bears and make noise in blind spots.
Wapiti Lake trailhead is one of the access points to the Pelican Valley area, which is known for major bear activity. In response to Wednesday's attack, park officials have closed the Wapiti Lake trail and posted a bear warning sign at the trailhead.
The hometown and identity of the victim in Wednesday's attack have been withheld pending notification of other family members.