- Location: Black Crater, west of Sisters
- State: Oregon
- Date: 2023/03/02
- Summary Description: 1 backcountry skier caught, partially buried-critical, and killed
- Primary Activity: Backcountry Tourer
- Primary Travel Mode: Ski
- Location Setting: Backcountry
- Caught: 1
- Partially Buried, Non-Critical: 0
- Partially Buried, Critical: 1
- Fully Buried: 0
- Injured: 0
- Killed: 1
- Type: HS
- Trigger: AS - Skier
- Trigger (subcode): u - An unintentional release
- Size - Relative to Path: --
- Size - Destructive Force: D2
- Sliding Surface: I - New/Old Interface
- Slope Aspect: E
- Site Elevation: 6488 ft
- Slope Angle: 40 °
- Slope Characteristic: Sparse Trees
Black Crater is a shield volcano in the Cascade Range in Deschutes county, Oregon. The mountain is approximately 8 miles west from the town of Sisters, OR. The mountain tops out at just over 7200’ and the vertical relief is approximately 2500’. The mountain has experienced at least one wildfire in recent years leaving many standing dead trees. Black Crater is within the Central Cascades zone covered by the Central Oregon Avalanche Center (COAC), and has become an increasingly popular backcountry touring destination in recent years.
The wind slab avalanche was unintentionally triggered by a skier at an elevation just under 6500 ft. at the top of a feature known as the ‘Lake Bowl’ on the east side of the mountain. The avalanche released on a major convexity where the slope went from low angle to 40+ degrees. The slope below is steep with many standing dead trees.
The skiers had been to Black Crater several times before but had never skied the slope where the avalanche was triggered on March 2.
The avalanche Danger was rated moderate on the day of the avalanche with the only problem listed being wind slabs.
Problem description for March 2:
“Most of the wind slabs formed during the last storm are trending toward stubborn to non reactive to triggering. There could be a few lingering pockets of wind slab on isolated terrain features that could still go, but I suggest paying more attention to new wind loading as the snow begins falling on Thursday. West winds will be moving snow as soon as it hits the ground. The incoming storm could drop 2-4" of snow by the afternoon and wind slabs will build on north through east and south aspects near and above treeline.
Look for wind slabs building below ridge tops, peaks and around features that catch blowing snow from cross slope winds. Most wind slab avalanches will be on the small side, however monitor the depth of wind deposited snow. As wind slabs become deeper, resulting avalanches can become larger.”
Link to archived forecast for March 2: https://www.coavalanche.org/forecasts/#/forecast/central_cascade/120918
In the week leading up to the avalanche, the region had received around 2 feet of new snow. Winds had mostly been out of the west and the temperature had remained cold for Oregon with daytime highs in the teens to mid 20’s Fahrenheit.
By early December, many areas in the central Oregon mountains had around a meter of snow on the ground. By mid december the avalanche center was reporting a persistent slab problem related to a layer of buried surface hoar. This weak layer was only active for a short period of time. After several days of unseasonably warm temperatures and heavy rain into the upper elevations around Christmas, this layer was deemed inactive and could not be found in most profiles. Mid January had little snow accumulation but towards the end of January snow began falling with one storm after another. By early March, low and mid elevations had a snowpack of around 2 meters deep. At this time, our avalanche problems were storm related with our typical rise and fall in danger with each storm cycle. See the two snowpack profiles in the time period leading up to the avalanche.
Events Leading to the Avalanche
A group of two skiers departed from Highway 242 (near the town of Sisters, OR) and snowmobiled on forest roads to the northeast side of Black Crater.
They followed an old skin track toward the summit along the northeast side of the mountain. They noted that it was snowing and windy but they did not see much blowing snow except for a few places near the summit. Upon nearing the summit, the two skiers did some snowpack evaluation. They decided to descend to the large east facing bowl above Black Crater Lake. Some locals refer to this as the ‘Lake Bowl’. They skied down adjacent to the summertime trail briefly, before moving east and finding their way to the top of the Lake Bowl. The top of the bowl ranges from 6200’ to 6500’ elevation. This elevation is typically below treeline in central Oregon. However, with much of the surrounding trees being dead and/or sparse, this location has the potential to experience wind effects more in line with near treeline elevations.
Skier 1 dropped into the Lake Bowl on a slope that is approximately 40 degrees steep. The entry into the slope is a major convex roll. As the skier crested the roll, he triggered a wind slab that propagated up to 20 meters to either side. Skier 1 was caught and carried down the steep slope with trees below. Skier 2 waited for the debris to settle. He did not have a visual on skier 1. He switched his transceiver to search mode and started making his way down the slope. He eventually located skier 1 by getting a visual on his backpack that was above the snow. Skier 1 had stopped with his head facing downslope against a tree. His head and torso were 6-18” below the surface.
Skier 2 contacted emergency services which initiated a response from Deschutes County Search and Rescue (DSAR) and personnel from the Deschutes National Forest.
DSAR was able to get a field team to the top of the Lake Bowl as dusk was approaching but did not reach skier 1 that day. Field team personnel noted heavy blowing snow and the crown of the avalanche was becoming covered by wind transported snow. DSAR returned the following day on March 3. On March 3, the avalanche danger increased to considerable due to an increase in wind-transported snow. DSAR personnel intentionally triggered a wind slab avalanche on the adjacent slope while on belay. They used ropes to belay team members down the slope to locate skier 1. Skier 1’s body was located and raised up to the top of the Lake Bowl and transported off the mountain via sled carry and eventually motorized transport.
On behalf of COAC our hearts go out to the family and friends of the people involved in this avalanche. With the backcountry community in Central Oregon growing every year, we have had an increasing number of close calls, but this was the first avalanche fatality in our area since 2014.
Figure 5: Snow profile from the Central Cascades forecast zone; February 20, 2023. This profile was conducted approximately 18 miles south of Black Crater.
Figure 6: Snow profile from the Central Cascades forecast zone; March 2, 2023. This profile was conducted approximately 18 miles south of Black Crater.