Fatal Glacier Grizzly Attack Report Confirms Hiker Emptied Bear Spray

On Sunday, May 3, 2026, at about 9:30 pm, Anthony Polio was attacked by a mature grizzly bear boar on the Mt. Brown Lookout trail in Glacier National Park. Polio had time to draw and empty his 7.9 ounce Bear Guard bear spray before he was killed by the bear. The official report on the incident has been released by the Interagency Grizzly Bear Committee (IGBC) Board of Review.  The Board of Review consisted of ten people, four from federal agencies, one from Wyoming Game and Fish, and five from Montana Fish, Wildlife, and Parks. From the official report, p. 10:

Claw marks on a burned tree and a displaced stone suggested that the bear launched its attack from this point (Photo 4). This is also where the discharged canister of bear spray was located. 

The bear spray can was fully discharged. The empty can weighed 84 g. A new, full can of the same brand with the same expiration date weighed 312 g, a difference of 228g. The advertised quantity marked on the label was 225g.

Fallen trees and poor light would have probably obscured the bear. As the bear attacked, the victim fell or was thrown downhill. His path was littered with personal effects beginning 10 ft below the trail (Figure 2). We believe the bear followed Mr. Pollio downhill, continuing the attack. Spatters of blood increased in frequency and volume down the hill. Mr. Pollio’s ear was found approx. 40 ft downslope. A large pool of blood marked the limit of his descent 93 ft below the trail, (Figure 3).

The initial attack site as determined by the investigation. 

First contact is believed to have been at the trail just before first tree across trail with bark worn off. The trail switches back to the right, uphill, just beyond the second deadfall across the trail with the bark worn off. The scent of bear spray lingered around the area where the trail switches back. 

The handwritten notes and sketch of the attack scene show some context and the probable routes taken by Polio and the grizzly bear.  The sketch shows an area with the scent of bear spray at the point the trail switches back to the south, going uphill. The top of the sketch is roughly to the West. The sketch shows the distance from claw marks to the point on the trail where the initial contact is believed to have taken place as seven feet.

In the sketch, the x-x, y-y, and z-z measurements appear to be from the trail to points below the trail, with x to be the furthest from the trail.

The investigators believe the attack occurred as Polio was coming down the trail, heading back toward the trail head. The investigators place the attack time about 9:30 pm, just at the end of civil twilight. The report lists “last light” as 9:24 pm. The Sunrise/Sunset tables Glacier National Park for May 3, 2026 list Sunset at 8:54:58 and End of Twilight at 9:29:02. pm. In mountainous terrain, atmospheric conditions and lighting from mountainsides and clouds mean those numbers can vary by several minutes. According to the report, the moon would not rise until 11:46 pm on May 3, 2026. Because the sky was mostly clear, the area would not have been completely dark. Light levels were low.

The temperature listed at West Glacier weather station was 58 degrees at 9:12 pm at an elevation of 3202 feet on May 3, 2026. The elevation where the attack occurred was over 2,000 feet higher, at about 5,300. The snow field was  only 800 feet above the attack site. The temperature at the attack site was likely lower than 58 degrees but above freezing. According to research done by Tom Smith on how temperatures affects bear spray, the reach of bear spray starts to be reduced at about 64 degrees F. Wind at West Glacier was light, at about 2 mph gusting to 7 mph. It is unknown what the wind was at the attack site when the bear attacked. As noted in the Tom Smith paper, wind can have a significant effect on bear spray.  We do not know what the temperature of the bear spray was when it was sprayed. The investigators were not able to determine if any bear spray contacted the attacking bear.

The distance from the claw marks to the trail, at 7 feet downhill, is remarkably similar to the distance at which Brian Murphy shot a grizzly bear which charged at him through bear spray on the same trail. That bear was also charging uphill, in 2014. In 2014, the .357 magnum shot stopped the bear when the bear spray did not. The estimated distance was 7-10 feet.

From 2003 to 2023, there were 211 independent grizzly bears which were killed in defense of human life in the lower 48, according to the U.S. Fish and Wildlife Service in 2025. Those fatalities averaged 13 per year, or about .64% of the grizzly bear population per year. Grizzly bear populations can easily increase at 7% per year. Alaska harvests about 6% per year. A harvest of 15% a year may be sustainable. Grizzly bear populations in the lower 48 states continued to increase through the entire period. While not stated, it is reasonable to assume the vast majority of fatalities of grizzly bears in defense of human life occurred with the use of modern firearms. The Fish & Wildlife Service did not differentiate between types of instruments used to kill the grizzly bears in self defense in the cited report.

The IGBC Board of Review Report gives recommendations for bear safety. One of the things they continue to recommend is bear spray. They do not mention firearms or handguns at all. Handguns, when fired, have been shown to be more effective than bear spray, when sprayed. The latest bear spray statistics show about 90% effectiveness when sprayed. The latest handgun statistics show about 98% effectiveness when fired. Anthony Polio is the eleventh person recorded in North America as having been killed by a bear after bear spray was sprayed in defense. No human has been recorded as being killed by a bear in North America where a handgun was present and fired in self defense against a bear.

Analysis:  Anthony Polio had time to recognize a threat, draw and empty his can of bear spray. This is at least five seconds or more. He would have had time to draw and fire multiple shots from a modern handgun carried in a modern holster.  While it can never be known if a modern handgun would have saved him, the numbers show his chance of survival would have been improved.

©2026 by Dean Weingarten: Permission to share is granted when this notice and link are included.

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