Detailed Accident Report

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Date: 2007-02-17
Submitted By: WWAN
Place: Mount Baldy, about 20 miles from Townsend
State: MT
Country: USA
Fatalities: 2
Summary: 3 snowmobilers caught and buried. 2 killed

OFFICIAL REPORT FROM THE GALLATIN NATIONAL FOREST AVALANCHE CENTER.

BIG BELT MOUNTAINS AVALANCHE FATALITIES

17 February 2007

SYNOPSIS:

Three snowmobilers were caught and buried in an avalanche resulting in two fatalities in the Big Belt Mountains northeast of Townsend, MT. The avalanche released on a southeast facing, wind-loaded slope. The slope angle was approximately 35-40 degrees, with the crown face averaging 3 feet deep. The avalanche was estimated to be 300 feet wide and 400 feet vertical with a runout angle of 24 degrees and debris 10-15 feet deep. The avalanche was triggered by the party on the slope. US classification of the avalanche is HS-AMu-D2-R3-O.

GPS Coordinates at the toe of debris:

N 46.42280

W 111.20307

Elevation: 8,330?

Maps of the accident site with red crosshairs denoting toe of debris:

(1:50,000)

www.topozone.com

(1:200,000)

www.topozone.com

WEATHER:

The weather data for this incident is from the town of Townsend, approximately 15 miles to the southwest and from the Tizer Basin SNOTEL site located at 6,880?, approximately 25 miles west of the accident site in the Elkhorn Mountains.

Saturday, February 17th was a sunny day with air temperatures near 32F at 8,500? (estimated). Over the past 8 days 1 inch of Snow Water Equivalency fell at the Tizer Basin site. Winds started to pick up later in the day on Thursday the 15th and blew hard on Friday the 16th. Speeds in Townsend averaged 25 mph with gusts reaching 65 mph from the west on Friday. From my observations at the scene (8,500?) I measured approximately 2 feet of new snow in a bowl that was obviously wind-loaded at the crown from westerly winds.

AVALANCHE:

JC (27) of Helena, Montana, KR (26) and BT (27) of Townsend, Montana were longtime friends and snowmobile partners. They were all expert riders with customized sleds. On the day of the accident JC and KR had shovels, but BT did not and none of the riders had avalanche transceivers or probe poles.

They met in Townsend at 0900 on Saturday, February 17th and were at the North Fork of Deep Creek Trailhead by 1000. They had set their minds to ride this specific bowl located southeast of Mount Edith in the Big Belt Mountains which they visited once before last winter. Riding into the bowl was difficult because the sleds would sink into the faceted, sugary snow at the ground. JC was the first to the bowl and waited for the others. He joked with them about how he waited because he wanted them around to dig him out in the event of a slide. They all knew they were in avalanche terrain and they also knew that the conditions might be hazardous from all the new snow and wind.

After a few low passes they met and discussed riding the slope that eventually slid. The last conversation all three had was about avalanches. They talked about taking a run up the hill and it was unspoken that they would all do it. The riding conditions were the best of the year with all the new snow.

BT took a run, turned to the right and got stuck. He was about 2/3 up the slope. JC rode to the left of him and got stuck too. KR was below, on the slope, watching them. JC saw BT take a few big lunges, but fall on his stomach in the deep, unconsolidated snow. This is when JC saw the avalanche, but he too was unable to move. The avalanche came over the top of him, tossed him violently and he thought he would die. His helmet was ripped from his head. He tried swimming and as the avalanche slowed he knew he should try and make an air pocket, but his arms were pinned. He saw a patch of light, then darkness before he came to rest. He was face down but was able to blow the snow out of his mouth. By arching his back he freed his neck and head. With wiggling he got his arms unstuck and dug himself out. He estimated he was under 6? of debris. He was 30 yards uphill of his sled. He saw BT?s sled to his right (the track was sticking out), and proceeded to search and dig for his friends. The time was approximately 12:30 pm. He estimates he spent 30-60 minutes looking for BT and KR, but was unable to locate them. He then spent about 1 ? hours digging his sled out of the debris. He rode to within a few miles of the trailhead before it broke down. He then hiked out with a badly twisted ankle along the road to the vehicles, arriving about 5:30 pm.

SEACH AND RESCUE:

Family, friends and 3 search and rescue organizations went into the scene that evening to locate the bodies. BT was found first with probing. He was 50? downhill of his sled under 2-3 feet of snow, face-down with his head downhill and his helmet missing. KR was also found by probing. He was located against a tree, on his side, 6-8? deep. His helmet was still on and his sled was approximately 50 feet uphill. Gallatin County Search and Rescue flew to the scene the next morning where the two bodies were flown out.

SNOWPACK:

A large part of the upper slope did not avalanche. This hang-fire was a safety concern so I limited my snowpack investigation to the toe of the debris. Slope angles and dimensions of the slide mentioned in the Synopsis are estimates. I dug a quick pit in undisturbed snow near the toe of the avalanche (8,330?). I found 80 cm of large grained faceted snow of Fist Hardness underlying 60 cm of new snow of 4-Fingered Hardness. I did no stability tests but could see that the snowpack almost doubled with snowfall the previous 8 days. Given the new snow and recent winds it?s my professional opinion that the slope failed on the layer of faceted snow. Near the crown the avalanche gouged down to the ground in rocky areas. The weak, large grained faces could not handle the load placed on it over the last 8 days from new snow and wind deposited snow. The slope was triggered by the 3 snowmobilers on the slope simultaneously. Although the Big Belt Mountains are not in our forecast area, for comparison, in the Bridger Mountains 35 miles to the ssw of the accident, the Gallatin National Forest Avalanche Center rated the avalanche danger HIGH on slopes steeper than 35 degrees.

Please contact me for more information or if you have questions. I can be reached at 406-587-6984 or dchabot@fs.fed.us.

Doug Chabot

Director

Gallatin National Forest Avalanche Center

www.mtavalanche.com

***MEDIA REPORTS***

Please visit: www.idahostatesman.com

Feb 18, 3:48 PM EST

5 dead after avalanches in Montana, Utah and Idaho

By SUSAN GALLAGHER

Associated Press Writer

HELENA, Mont. (AP) -- Weekend avalanches killed five people in Montana, Utah and Idaho, with one bruised survivor traveling miles by snowmobile and on foot to reach help, authorities said.

In Montana's Big Belt Mountains, the bodies of two snowmobilers caught in an avalanche were found by searchers early Sunday and removed by helicopter later in the day.

That avalanche happened Saturday at the base of Mount Baldy, about 20 miles from Townsend. A survivor traveled the 15 or 20 miles back to the trailhead, initially by snowmobile and then on foot after the machine became stuck, Lewis and Clark County Sheriff Cheryl Leidle said.

Upon reaching a pickup truck at the trailhead, he used a cell phone to call for help.

"It would appear the avalanche drove them into a grove of trees downhill from the avalanche itself," Leidle said.

The names of the three men were not immediately released. Leidle described them as friends in their 20s from the Townsend area.

In Utah, two snowmobilers died in separate avalanches on Saturday.

Zachary Holmes, 16, of Farr West, was buried by an avalanche estimated to be 300 feet wide near Tower Mountain in the Uinta Mountains, about 14 miles southeast of Heber City, the Wasatch County sheriff's office said.

Holmes was wearing a helmet and an avalanche beacon, deputy Michael Graves said. Following the beacon's signal, his cousins found him and dug him out of the snow. He later died at the University of Utah Hospital, authorities said.

Earlier Saturday, a snowmobiler on Signal Peak in southwestern Utah triggered the avalanche that killed him, the Sevier County sheriff's office said.

That man, whose name was not released, was climbing the back side of the peak when the avalanche buried him in an estimated 8 feet of snow, authorities said.

In Idaho, the Bonneville County Sheriff's Office in Idaho Falls confirmed the death of a Utah man in an avalanche near Palisade Peak. His name was not immediately available.