WILDLIFE ENCOUNTERS -- In July, Yellowstone Park reported the first human fatality in 25 years from a grizzly bear attack.

Now there are two in a single season.

Yellowstone National Park officials say a grizzly bear killed a 59-year-old Michigan man whose body was found by hikers last week, according to the Associated Press.

The victim was identified Monday as John Wallace of Chassell, Mich.

Wallace’s body was discovered along a trail about five miles from the nearest trailhead. Results of an autopsy released Monday concluded Wallace died as a result of traumatic injuries from a bear attack.

It is the second time a visitor to the park has been killed by a bear this year.

Investigators were not immediately sure whether the grizzly caused the man’s death or disturbed his body after he died.

“Bears are opportunistic when it comes to food sources,” Yellowstone spokesman Al Nash said earlier. “It’s very clear that there was a bear around the victim’s body. What we don’t know is whether this was a bear attack, or whether the bear came upon this man’s body after he died.”

Authorities say the man likely died Wednesday or Thursday. His death comes after a female bear attacked and killed a 57-year-old California man on the popular Wapiti Lake Trail, several miles away from where the Michigan man was discovered Friday.

The female bear that killed the California man was not killed because officials said the sow was only defending its cubs and had not threatened humans before.

Yellowstone Superintendent Dan Wenk has said that the hiker was found with a snack bar in his closed backpack, but that it appears the grizzly did not try to get at the food.