Detailed Accident Report

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Date: 2007-02-04
Submitted By: CAIC; M. Mueller
Place: East San Juan Mountains, ~2 miles NW of North Peak.
State: CO
Country: USA
Fatalities: 1
Summary: 1 snowmobiler caught, buried, and killed


East San Juan Mountains, bowl on SE shoulder of Pt. 12,494, approx 2 miles NW of North Peak.

February 4, 2007

One snowmobiler buried and killed


Two snowmobilers were highmarking a southeast facing bowl. The upper snowmobiler triggered an avalanche from a low angle terrain feature. The avalanche propagated across the bowl. The lower rider had turned and was descending, and did not see the avalanche above him.


Snowfall in the East San Juans has been just above average for the winter to date. Snow fell early and often through the winter. Significant surface hoar layers have formed during brief clear periods, particularly in December. In the five days prior to the accident, 16.5 inches of snow fell at the CAIC/CDOT snow study plot at the Wolf Creek Pass (approx. 9 miles W of the accident site). Temperatures were very cold (minimum ?12?F) and snow was low density. The day before the accident strong northwest winds averaging in the teens and gusting in the 40-50 mph range caused considerable snow transport throughout the East San Juans. Clear blue skies and mild temperatures dominated the day of the accident. Air temperature at Wolf Creek Pass at the time of the accident was 23?F.

Events leading up to the Accident

The morning of 2/4/07, three men headed up the Beaver Creek groomed snowmobile trail into the high country around North Peak. An ungroomed side trail took them into a large east through southeast facing bowl on the southeast shoulder of Pt. 12,494. They stopped on a large bench in the middle of an obvious large avalanche path. A recent avalanche (SS-N-R2D2-O/G) was visible on the climber?s left side of the bowl. It had recently run in the period between 2/1 and 2/4.

While one rider remained at the bottom of the bowl two riders began to high mark the extreme right hand side of the bowl. As one rider reached the ridge he triggered an avalanche that involved the entire right hand side of the bowl. Unfortunately, the other rider turned left into the bowl about halfway up unaware that an avalanche had been triggered. As he descended the rider at the bottom frantically waved to catch his attention, but the avalanche overran him before he could avoid or outrun it. The rider who triggered the avalanche was not caught and raced to the bottom of the bowl.

The Avalanche

The avalanche was triggered from a relatively low angle subtle convex role at the extreme right side of the bowl and propagated 900 feet to the west. The avalanche ran on a weak layer of old surface hoar that formed on or about 12/15. This season, several avalanches have run on this weak layer.

Slope angle at the trigger point was 23? (yes, 23?). The slab was also thickest here, 50 inches. Slope angles in the main part of the starting zone were typically 37?, and 40? at the steepest point measured. The aspect ranged from east-southeast to southeast. The crown height averaged 30 inches. The snow surface was very hard (knife hard).

A mid-slope cliff band stretched across the entire bowl. Considerable debris stopped on a bench above this cliff band, but as the debris flowed over the cliff band more avalanching occurred, with much of this area sliding to the ground. The slope angle below the cliff band was 37?. The slide descended 800 vertical feet and stopped where the slope angle eased to 5?. The avalanche debris exhibited both hard slab and soft slab characteristics and is classified HS/SS-AM-R3D2.5-O/G.


The victim?s snowmobile came to rest at the toe of the debris partially buried and still running. Initial rescue efforts were focused near the snowmobile. The group did not have any avalanche rescue equipment, but began to search immediately. At 1116 hours the Rio Grande Country Sheriff?s Office received a cell phone call from one of the party stating that a party member had been buried in an avalanche. Rio Grande County Search and Rescue respond. One of the party members met Search and Rescue at the trailhead and guided them back to the location. At 1410 hours, probing found the victim buried four feet deep, 8 to 10 feet south of his machine at the toe of the debris.

Mark Mueller, 2/6/07

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Man, 46, dies in avalanche

Victim was snowmobiling in San Juan Mountains when swept under.



SOUTH FORK - A 46-year-old Rio Grande County man was killed Sunday after an avalanche swept down on him while he was snowmobiling in the nearby rugged San Juan Mountains.

Rio Grande County Sheriff Brian Norton identified the victim as Walter Martinez whose home is between South Fork and Del Norte, was snow machining.

Norton said Martinez and two friends, whose names were not released by the sheriff, were snowmobiling near North Mountain, about 10 miles southwest of South Fork, when the avalanche occurred about 11 a.m.

Norton said Martinez?s companions, one from Denver and the other a local resident, saw a cornice of snow break off and the avalanche bearing down on Martinez and tried to warn him with hand signals.

?(Martinez) turned to look and tried to get away, but it was too late,? Norton said.

The companions called for help on a cellphone.

Martinez?s body was found under an estimated 4 feet of snow shortly after 2 p.m., according to Norton. He said the body was dug out and carried in a four wheel-drive vehicle to a waiting ambulance near Beaver Creek Reservoir.

Attempts to revive Martinez failed.

Rio Grande County Coroner Norman Haug said an autopsy will be performed this week in El Paso County.

Martinez, a local contractor, is survived by his wife and two children, aged 7 and 9.