On Sunday, big-mountain ripper Jamie Pierre was killed in an avalanche. The collective skiing community continues to mourn the loss of a true pioneer. Yesterday, the Utah Avalanche Center posted an official summary regarding the slide. We've posted the information below:

Official Accident & Rescue Summary, as posted on https://utahavalanchecenter.org/

FINAL REPORT 11/14/11

Thanks to the Snowbird Ski Patrol and Snow Safety for their assistance.

Two men in their 30s left the closed Alta ski area with the intent to ride the well known terrain of Alta and Snowbird.  Neither ski areas are open yet and have yet to conduct any avalanche control within their boundaries.  We interviewed the victim's ski partner.  To say he was shaken up is an understatement.

While neither had any rescue gear or formal avalanche training, they were both expert skiers and knew the terrain well.  They had not consulted the avalanche advisory that morning in which the danger was rated Considerable to High.  They continued to Snowbird via Baldy and accessed the Peruvian Cirque to gain the Gad Valley.  While ascending out of the Peruvian Cirque they remotely triggered a large avalanche that covered their tracks that they had just made.  It's unclear whether they realized they had triggered this large avalanche.  They gained the ridge and prepared to drop into Gad Valley.

With the partner watching, the victim dropped into the slope, immediately triggering the slide.  He was carried approximately 800 feet through steep rocky terrain and reportedly went over a small cliff band and came to a stop only partially buried.  The partner went down to help the victim and called for a rescue, alerting both the Snowbird Ski Patrol and Wasatch Backcountry Rescue, who subsequently accessed and evacuated the victim.

• Observer Name: Kobernik and Hardesty
• Observation Date: 11/13/2011
• Occurrence Date: 11/13/2011
• Occurrence Time: 2:30pm
• Region: Little Cottonwood Canyon, South Chute in Gad Valley. Salt Lake.
• Avalanche Characteristics:
• Elevation: 10300'
• Aspect: Northwest
• Slope Angle: 40
• Trigger: Snowboarder
• Trigger: additional info: Unintentionally Triggered
• Avalanche Type: Soft Slab
• Weak Layer: Facets
• Depth (avg): 16"
• Depth Range: 14" to 20"
• Width: 150'
• Vertical: 800'

TERRAIN SUMMARY

The first two photos below are of the large avalanche that the party triggered in the Gad Valley which did not catch them.  The last two are of the avalanche site of the fatality.

WEATHER AND AVALANCHE HISTORY

The weak snow structure has been well documented over the last few weeks.  Here is the time line.

Oct 5-6: Significant storm produced 1 to 1 1/2' feet of snow.  Warm weather melted much of this snow but some did linger on the more northerly aspects.  The melt-freeze process in early October produced a stout crust.  This crust varies in thickness depending on aspect.  It's thicker on east and northeast slopes, thinner on the more due north.  Colder subsequent weather deteriorated this snow forming large grained facets below this crust, especially on the northerly aspects.

Oct 15 & Nov 1: Oct 15 had a small storm with a two week colder clear period which faceted this snow above the melt freeze crust.  Nov 1 had another small storm whose snow also deteriorated rapidly to facets.  It is these two events that, combined, form the weak layer that is causing the collapsing and avalanches.

Nov 5: Around a foot of low density snow fell.  This gave us the first hint on how the previous snow would behave.  On Oct 6 a skier triggered a small slab avalanche in Collins Gulch.  (Details)  The weak layer was the faceted snow from Oct 15 & Nov 1.  On Oct 7, another skier triggered avalanche was reported. (Details)  During Oct 8-11, numerous reports were coming in of backcountry travelers experiencing collapsing of the snowpack, including THIS one from the Peruvian Gulch which illustrates the poor structure.

Nov 12: A storm rolled in producing 5-9" of dense snow.  A ski touring party in Gad Valley was experiencing collapsing and remotely triggered to small avalanches. (Details)

Nov 13: The second portion of the storm brought another 5 to 10" of snow with wind.  With all the previous observations and the new storm snow, the Utah Avalanche Center rated the danger at Considerable and possibly High if snowfall kept up harder then expected. (Nov 13 Advisory)

The fatal avalanche had the same snowpack structure as that of all the collapsing and other avalanche activity over the week of Nov 6 through Nov 11.

GENERAL COMMENTS

This incident is difficult for many reasons.  We heard of over 10 human triggered avalanches on the day of the fatality, primarily in the upper elevation terrain in the unopened Alta ski area.  Many of those touring these slopes know the terrain well and are used to riding the terrain when the area is open and the ski patrol has already conducted avalanche control work.  There is always a reinforced feeling of safety. This terrain MUST be treated as if it were the backcountry, proper backcountry protocol must be adhered to (riding one at a time, not skiing on top of others, etc), and personal responsibility is critical (ie – be prepared with avalanche rescue gear, 1st aid equipment, and a repair kit.)

Another word on the incidents (Gunsight at Alta and this Gad Valley one).  The rescue teams from the ski areas and Wasatch Backcountry Rescue often put their necks out on the line to access and evacuate an injured party.  It was reported that other parties at Alta continued to ski and knock down avalanches into Greeley Bowl while the rescue was in progress.  Creating another incident during this situation is unacceptable.