Dave’s Wave is the name given to a terrain feature found in the backcountry between Arapahoe Basin Ski Area and Loveland Pass, Colorado. The feature is a vertical cornice that starts well above tree line at 12,800’ on the SE face of Pk. 13,117’. It is located near the mid way point between Grizzly Pk. (13,427’), to the south and Loveland Pass to the north-north west. The ridge line is the boundary between Summit and Clear Creak Counties, with the run located in Summit County. The known avalanche path goes from 12,900’ to the valley floor at 11,200’, but has not run full track in many years.
The start zone faces 190*S and turns to face 230*SW at the "elbow", which is near the top of another feature known as the "Ironing Board" near 12,200’. The start zone hovers around 35 degrees in steepness. Dave’s Wave is ridden 100s of times per season and avalanches approximately 3-4 times each season. This was the first avalanche in the path for the 07/08 winter season.
The run is clearly visible from A-Basin Ski Area, and US Route 6. If you see ski or board tracks in the area, there is a bit of a "rad" component to seeing them.
This area of Colorado has seen above normal precipitation, below normal temperatures and above normal winds. Winter started out slow with a significant precipitation event in early November followed by an extend period of high pressure and warm temperatures. Mid December, winter decided to come back with a vengeance. First with cold temperatures followed with back to back storm cycles depositing copious amounts of snow accompanied with strong winds. North west winds on our weather site located near the summit of Loveland Pass were in excess of 100mph. During the turn of the year, more snow accompanied with west south west winds pounded the area once again. The avalanche danger hovered between HIGH and CONSIDERABLE at and above tree line on all aspects with several different avalanche watches over a three week period. After the first of the year, west facing aspects above tree line were nearly devoid of snow due to the consistently strong winds.
Skier A~10 season veteran backcountry skier in the area. Skis between 150 and 200 days each season, mixing in area and backcountry. Has skied the same line 100’s of times before, but this was his first time this season. Has backcountry skied many times this season covering all aspects and elevations in the Loveland Pass vicinity.
Skier B~10 season veteran backcountry skier in the area. Skis between 150 and 200 days each season, mixing in area and backcountry. Has skied the same line 40-50 times before and this was his second time this season. He also skied it back on 12/30 or 31 of 2007.
Jasper the dog, enthusiastic backcountry traveler.
Skier A and B ski together very frequently, are close friends, roommates and communicate very well in backcountry settings.
These guys live to ski daily and work at night. They have more skis than furniture. More ski related books, maps and photos than wood for their stove to heat their house. Ski addicts to the core. They are connected, known and respected in the community for their local knowledge and skiing ability. They are true ski locals. They each have nick names at their local ski area; A-Basin.
Both Skier A and B listen to hotline and view the website for the CAIC daily; actually, every morning. During the interview this was questioned and they really do. They discuss the advisory over coffee and some times through the walls in their house while still in bed. They did view the CAIC website the morning of the incident. The morning of the incident, they discussed the advisory driving up to the "pass".
Between the two of them, they had dug several snow pits in the backcountry in the area (as recent as two days prior to the incident), however, they had not dug a pit on south through west aspects…yet.
Avalanche activity, both human triggered and natural had occurred on NE-SE-SW aspects, at and above tree line. With in the previous 24 hours, 6 hard slab avalanches had occurred, all of which were visible from Hwy 6 and from the top of the pass.
Due to the above mentioned weather, the general theme with the snowpack structure was hard slab sitting above weak, large faceted grains. Snow coverage ranged from completely bare, well above tree line on west aspects (due to severe wind scouring) to above tree line, easterly start zones being 2 plus meters deep. In general, the structure could be broken down into three sections: the top third was a mixed bag of soft slab and surface facets, the middle third hard slab and the bottom third large faceted grains. Two avalanche problems exist: shallow wind slab and deep slab instability. Avalanches were definitely being triggered in the surface layers and then they were stepping down, sliding on the ground.
The Avalanche Danger was rated as CONSIDERABLE at and above tree line on N-E-S-SW aspects. MODERATE elsewhere.
Act 1:
Skier B called Skier A
early in the am (skier A spent the night at a friends), asking him if
he would like to ski Dave’s Wave. He also expressed that he wanted to
get Jasper out for some exercise as the dog had not been out in a few
days.
Act 2:
Skier A agreed with the goal and came home quickly to get
ready for the day. They drove in two cars to make the shuttle easier,
leaving one car in a pull out near the CDOT barn at the base of
Loveland Pass and close to the bottom of Dave’s Wave. As they drove the
other car up to the top of the pass, they discussed the current winds
and altered their descent route to ski the "Ironing Board" instead. The
Ironing Board is located just skiers left of Dave’s Wave. Terrain wise,
it is typically a safer line choice than Dave’s because of two main
terrain factors: first, it is a slightly less steep line (low 30s) and
second, is less susceptible to wind loading from west and north west
winds. It does tend to get stripped from west and south west winds. It
does however, terminate at tree line where you need to choose between
continuing down through very dense trees or exit to skiers’ right, back
into the run-out gulley at the lower end of Dave’s Wave.
Act 3:
They parked at the top of the pass and were hiking
(carrying skis) up the ridge to the east of the pass by 10 am. They did
not notice the recent activity. They acknowledged reading about the
activity in the advisory, but did not see the signs. The winds at the
top of the pass were moderate and cold. Note: I had driven up to the
pass from the other direction about 30 minutes prior to skier A &
B. Stopping at the summit, I noticed the recent avalanche activity and
took photos of them. I quickly left the summit because it was cold and
windy. I wanted to get out of the wind. Skies were the typical bluebird
that Colorado is famous for.
Hiking up the ridge there was little to no talking. It was the put your head down and keep moving scenario. Nearing the summit of the first 13er along the ridge, Skier A said to skier B “this sucks!” They were mid way into a 45 minute to 1 hour hike on a highly elevated ridge line that is very exposed to the weather. They arrived at the top of Dave’s Wave by 11:00 am. The winds had eased some and the snow surface was "full on sustrugi". The first 500’ of the descent required the snow plow; full on survival skiing techniques. They had skied the same line over 50 times together in the last 5 years.
Act 4:
Skier B made a ski cut from the top of the Dave’s Wave
vertical cornice to skiers left (towards the top of the Ironing Board).
Skier A then made a ski cut just above Skier B’s cut; both with no
results. As they continued to descend, Skier A said to Skier B "I’m
crossing and I’ll follow you" to the top of the Ironing Board. The snow
surface was thin and full of exposed rocks. By about 11:30 they had
skied to the bottom of the Ironing Board. Skier A skied first (one at a
time), with B and the dog second/third. Riding conditions on the
Ironing Board were excellent.
Skier B had originally though of exiting to skiers left but quickly found "sugar snow". So, they decided to "milk" a few more turns because the snow was so good, by exiting to the skiers right, into the gulley below Dave’s Wave. Skier B went first and the dog followed. The snow was deep. Skier B exited into the trees near the bottom of the gulley and called up to Skier A to start his descent.
Skier A entered the gulley and the snow "was great". He quickly approached the dog and passed him. Skier A actually said "hey Jasper!" as he passed. He too exited the gulley to the left. When he did, he turned to look up at the dog and noticed the avalanche coming down and engulfed the dog. He yelled at Skier B to back up into the trees. Skier A held tightly onto a tree while trying to keep an eye on the dog. The powder cloud closed down visibility for 20-30 seconds. Skier A noticed that the cloud felt more like facets than powder.
After the cloud settled, both skiers scanned the snow surface for the dog…no dog. Skier A quickly put on his skins and started climbing back up the gulley to the last seen location. Looking at his watch, the time was 11:53. They both started probing the gulley. One of the skiers has a 320 cm probe pole and hit ground all but two times.
They called the ski patrol at A-Basin from a cell phone to say they were okay but were probing for their dog Jasper. Members from the Summit Country Rescue Group were paged prior to the call and deployed to the scene. The team made contact with the group and were told to stand down. Skier A and B discontinued their probe search for the dog at 4:15. They were back at the car near the CDOT barn by 4:30.
They were not aware of the sympathetic slide that occurred to the Skiers Left of the Ironing Board. Some maps call it "Grizzly 2". It is a "Y" shaped path starting above treeline and frames the Ironing Board with Dave’s Wave.
I asked them both separately how they would answer the decision making trap and alpine truth questions. This is how they answered them. Prior to each question, I explained what each "trap" meant. More on FACETS here, and on ALPTRUTH here.
|
Decision Trap |
Skier A |
Skier B |
|
Familiarity |
YES |
YES |
|
Acceptance |
Maybe…"not really" |
Maybe…"somewhat" |
|
Commitment |
YES |
YES |
|
Expert Halo |
NO |
NO |
|
Tracks |
NO |
Yes~ Wanted first tracks |
|
Social Consensus |
NO |
NO |
3.5
|
Indicator of Instability |
Skier A |
Skier B |
|
Avalanches |
YES |
YES |
|
Recent wind Loading |
YES |
YES |
|
Avalanche Path |
YES |
YES |
|
Terrain Trap |
YES |
YES |
|
Danger Rating |
YES |
YES |
|
Unstable Snow |
NO~ they did not experience |
NO |
|
Thaw Instability |
NO |
NO |
5
Skier A said that he would not have skied into the gulley.
Skier
B said that he would have skied directly down below the Ironing Board
into the dense trees. He also said that he would consider getting two
old frequency beacons to use when skiing with a dog.
Sawtell 20080120