Signs indicating an area closure due to bear activity on June 30, 2016 after Brad Treat was killed while mountain biking near West Glacier. Greg Lindstrom | Flathead Beacon

Updated: June 29, 9 p.m.

A West Glacier man was killed by a grizzly bear Wednesday afternoon while riding his mountain bike on a forested trail in the Halfmoon Lakes area south of Glacier National Park.

Flathead County Sheriff Chuck Curry identified the victim as Brad Treat, 38, of West Glacier. Treat grew up in the Flathead Valley and graduated from Flathead High School, where he was a standout distance runner, in 1996.

Authorities have closed the area around Halfmoon Lakes as the investigation continues. As of 8:30 p.m., the bear that attacked Treat had not been found.

Treat and another man were mountain biking on U.S. Forest Service land near Halfmoon Lakes on Wednesday, according to Curry. The initial investigation suggests the two bikers surprised the bear around 2 p.m. and Treat was taken off his bike by the animal. The second rider was able to escape uninjured and summon help.

Treat was pronounced dead at the scene.

The Flathead County Sheriff’s Office, the Montana Fish, Wildlife and Parks’ Wildlife Human Attack Response Team and the U.S. Forest Service are investigating the incident.

Staff at the nearby West Glacier KOA along Halfmoon Flats off U.S. 2 said the campground guests have all been briefed of the incident.

Treat worked as a law enforcement officer for the Forest Service.

“Brad was an integral member of our area law enforcement team and a friend to us all. Our thoughts and prayers are with his family tonight,” Curry said.

Growing up in the valley, Treat developed into one of Montana’s best distance runners and helped form the long-distance dynasty at Flathead High School in the mid-90s. Along with his all-state accomplishments and tireless dedication, Treat’s kind-hearted demeanor left a lasting mark on the Brave program for years to come, according to his former coach, Paul Jorgensen.

“He’s one of the nicest kids I’ve coached,” Jorgensen, who has coached Flathead runners for nearly 40 years, said Wednesday night after learning of Treat’s death.

“One thing that really impressed me about him, we were running at the Missoula Invitational (cross country meet) and he was the top runner. He finished first and then he turned around and congratulated every kid that finished. That really impressed me. I told my kids that story off and on over the years and then my kids started doing that, too. Brad’s the one who started that. That’s the kind of kid he was.”

With Treat as one of its all-state distance runners, Flathead won a cross country state championship in 1994 and track state championships in 1995 and 1996. Treat’s 1996 time of 9:14.30 in the 3,200-meter race was the fastest in Montana history by a prep runner until it was broken three years later. He won individual state championships in the 1,600 and 3,200 as a senior.

“He was a really good runner but he was also a kind-hearted person who cared about people,” Jorgensen said.

Jorgensen said Treat’s death is a tragic loss for the entire Flathead Valley, the running community and the Flathead High School community.

The death is the first fatal grizzly attack in Northwest Montana since 2001, when an elk hunter was killed on the Blackfoot Clearwater Game Range near Ovando.

Grizzly bear attacks are rare in the Glacier region but not unheard of. Since Glacier National Park was created in 1910, there have been 10 fatal grizzly attacks in the national park, the most recent in May 1998 when a 26-year-old man was killed hiking in the Upper Two Medicine Valley.

Northwest Montana is home to the largest grizzly bear population in the lower 48 states with approximately 1,000 bears living in the region.

There have been six fatal grizzly bear attacks since 2010 in the Yellowstone region of Montana, Wyoming and Idaho.

This story will be updated when more information becomes available.