Investigators unsure of cause behind fatal grizzly attack in Yellowstone

Government investigators are unsure of the cause behind a fatal grizzly bear attack in August on a hiker in Yellowstone National Park. (USFWS photo by Terry Tollefsbol - click to enlarge)

Government investigators are unsure of the cause behind a fatal grizzly bear attack in August on a hiker in Yellowstone National Park. (USFWS photo by Terry Tollefsbol - click to enlarge)

By Ruffin Prevost

CODY, WYO. — Investigators don’t know why an experienced hiker from Michigan was killed by one or more grizzly bears in August in Yellowstone National Park, but DNA evidence shows at least three different grizzlies were at the incident site.

One of those was an adult female grizzly bear who was tied to a July fatal mauling in Yellowstone about eight miles away, according to a report released Monday from an interagency team of state and federal investigators.

The body of 59-year old John Wallace of Chassell, Mich., was discovered Aug. 26 along the Mary Mountain Trail in Yellowstone’s Hayden Valley.

Investigators could not determine conclusively which bear or bears initially attacked Wallace or why. Other bears may have later fed on his body.

Less than two months earlier, hiker Brian Matayoshi, 58, of Torrance Calif. was killed by a female grizzly bear with two cubs along the Wapiti Lake trail. Investigators believe that attack was prompted by a surprise encounter, and witnesses report that Matayoshi ran from the bear, likely prompting a chase response.

The 250-pound female that killed Matayoshi was euthanized after Wallace was attacked, and her two cubs were removed from the wild. Investigators at that time and again in Monday’s report cited DNA evidence that confirmed the adult female was present at Wallace’s body.

Monday’s report confirms that at least one of her cubs was present as well. She may have been the bear that attacked and killed Wallace, and members of that family group probably fed on the body, according to investigators.

There were no witnesses to the attack on Wallace, and investigation of the incident scene was complicated by rain and hail following the attack and the presence of several bears in and around the area.

Investigators surmised that Wallace was not hiking at the time of the incident. His pack was off and a partially eaten energy bar still in its wrapper was found near his body, indicating he may have stopped for a snack, the report states.

Wallace is described in the report as an organized and experienced backcountry hiker, but he was not carrying bear spray and he was hiking alone. A sign at the Mary Mountain trailhead warns hikers that they are entering grizzly country and advises hiking in groups and carrying bear spray.

Bear encounters are not uncommon in the greater Yellowstone area, but fatal attacks are relatively rare. The two maulings in July and August marked the first fatal grizzly attacks on humans in Yellowstone since 1986.

The attack on Wallace prompted weeks of aerial reconnaissance and tracking as well as trapping efforts that captured 13 individual grizzlies. None were captured at the site of the Wallace attack.

The two cubs whose mother was euthanized were transferred to the Grizzly and Wolf Discovery Center in West Yellowstone, Mont.

Contact Ruffin Prevost at 307-213-9818 or ruffin@yellowstonegate.com.

One thought on “Investigators unsure of cause behind fatal grizzly attack in Yellowstone

  1. Dear Yellowstone Gate
    I am 11 and in reading we just read about the grizzly bear I think it was intresting it was called”Hunting A Killer” I hope you come up with more cool stuff like this one again….BYE!!BYE.