UDOT PLANNED AVALANCHE CLOSURES!!

Accident: West Bowl

Observer Name
Brett Kobernik
Observation Date
Monday, December 4, 2006
Avalanche Date
Sunday, December 3, 2006
Region
Salt Lake » Big Cottonwood Canyon » Silver Fork » West Bowl
Location Name or Route
Elevation
9,900'
Aspect
North
Slope Angle
37°
Trigger
Skier
Trigger: additional info
Intentionally Triggered
Avalanche Type
Soft Slab
Weak Layer
Facets
Depth
2'
Width
1,500'
Vertical
600'
Caught
3
Carried
3
Buried - Partly
1
Buried - Fully
1
Accident and Rescue Summary

Accident Summary:

Three skiers left the town of Alta Tuesday for a ski tour into Big Cottonwood Canyon. They ascended the south facing slope above the town of Alta. They decided to ski down into the West Bowl of Silver Fork. This was an east northeast facing slope. When they regrouped, it was decided to ascend the more northerly facing slope to regain the ridge. As they were ascending, the slope fractured and avalanched. All three were caught. One grabbed a tree and was not carried far but did lose a ski. Another was carried around 30 feet and was buried enough so that he was not able to move without digging himself out. The third was missing.

Rescue Summary:

After determining that one person was missing from the party, the other two initiated a search with avalanche transceivers. They were aided by another nearby solo skier. The location of the missing person was quickly located between 100 and 200 feet downhill from where he was caught and they struck him with the first attempt with an avalanche probe. He was reportedly buried around 4’ deep. When they uncovered him, he was face down. They checked his airway for snow but it was already clear. They noticed that he was breathing but it was labored. They started to treat for hypothermia by placing the victim on top of backpacks and putting on spare layers of clothing. Rescuers were contacted via a cell phone and a life flight helicopter was dispatched. The victims labored breathing improved and he became coherent. He was able to ski himself down around 200 feet to where the helicopter was able to land. He was then evacuated.
Comments

All of the skiers involved had some formal avalanche training but two of them had more training then the buried victim. They chose the West Bowl of Silver Fork because of its low angle options which would be appropriate for the conditions that day. They performed some snow stability tests on the way up from Alta. They noted some weakness within the new snow. They were also aware of faceted snow near the ground on northerly facing slopes. They did not experience any cracking or collapsing and successfully skied one run. This is when things started to go wrong. They decided to walk up a northerly facing slope to regain the ridge and then walk east on the ridge. It appears this deviated from the original plan of sticking to low angle terrain. Perhaps since they successfully skied the run and did not see any cracking, collapsing, or other avalanches, this influenced their decision. Excitement about the new ski season could have also played a role. At least one member of the party had reservations about some of the decisions but did not speak up. Later when the group discussed the accident, the other two had reservations as well but there was not complete communication. This fits into the “no leader” category where no one is in charge of making sure complete communication is occurring. Many accidents occur due to communication problems and no one is immune to making similar mistakes. It should be noted that this was a text book example of a perfect rescue which was accomplished only because the touring party had the proper rescue gear and was trained in using it.

Comments
This is the north facing slope where the accident occurred on Nov 14. The red arrow indicates the skiers location when the slope avalanched. The yellow arrows are each flank of the avalanche. The purple arrow is the avalanche that released sympathetically to the first one.
Comments
This is above where the skiers were caught. This is less then 1/4 of the size of the avalanche.
Comments
This is looking back down what is left of the skin track from about where the person breaking the trail was located. The stars indicate approximate locations of the other two skiers.
Coordinates