A second hiker has been killed by a grizzly bear in Yellowstone this summer, a not so subtle reminder that America's first national park is a wild and not tamed landscape.

Park officials say 59-year old John Wallace has been positively identified as the man found dead on a trail in Yellowstone on Friday, Aug. 26, 2011.  Wallace was from the community of Chassell, in Michigan’s Upper Peninsula.

His body was discovered Friday morning by two hikers along the Mary Mountain Trail.   The twenty-one mile long trail crosses the center of Yellowstone, connecting the west and east sides of the lower portion of the Grand Loop Road.

Wallace was discovered along the trail, about five miles west of the Hayden Valley trailhead, which is off the Grand Loop road between Mud Volcano and Canyon Junction.

He was traveling alone, and had pitched a tent in a park campground sometime Wednesday. Rangers discovered signs of grizzly bear activity at the scene Friday afternoon, including bear tracks and scat.

Results from an autopsy conducted Sunday afternoon concluded that Wallace died as a result of traumatic injuries from a bear attack. The Mary Mountain Trail, the Cygnet Lakes Trail, and the section of theHayden Valley west of the Grand Loop Road have been closed to hikers.

Park rangers, wildlife biologists, and park managers continue their investigation of the incident. Visitors are advised to stay on designated trails, hike in groups of three or more people, be alert for bears, make noise, carry bear spray, and not to run upon encountering a bear.

Hikers and backcountry users are encouraged to check with staff at park visitor centers or backcountry offices for updated information before planning any trips in the central portion of the park. 

This incident is the second grizzly-related human fatality in Yellowstone.  A California hiker was mauled and died during an incident along the Wapiti Lake trail earlier. That deadly encounter was the first in Yellowstone in 25 years.

Yet it comes in the wake of rising concern about roadside visitors coming in close contact with grizzlies in both Yellowstone and Grand Teton national parks while attempting to view and photograph them. 

Read the earlier blog to watch videos of how absurdly close to bears some have ventured .