Colorado Avalanche Information Center stresses planning, education in report on fatal slide

This photo looks up toward the crown of a fatal avalanche on Hoosier Pass. Two snowshoers and their dog were caught and buried just downslope of this point.
Colorado Avalanche Information Center/Courtesy photo

The Colorado Avalanche Information Center has released its final, more detailed report on the Jan. 9 avalanche that happened on North Star Mountain on Hoosier Pass. The avalanche killed Hannah Nash, 25, and Drake Oversen, 35, of Colorado Springs as well as their dog, Valerie, while they were snowshoeing.

According to the report, the snowshoers began their trek to Crystal Lake along a U.S. Forest Service road.

“It is easy to imagine how the pair went out for a casual snowshoe with their dog and unknowingly hiked into avalanche terrain,” the report stated.

The avalanche ran 100 vertical feet and was 370 feet wide, with the crown — where the snow broke off and slid — ranging from 3 to 10 feet high, according to the report. The avalanche debris averaged 6 feet deep and partially buried the road, which is open to motorized travel in the summer.

“The take-home message really is just planning,” Colorado Avalanche Information Center Director Ethan Greene said. “These folks, they did something all of us do. They went out for what felt like a very simple, recreational day, and they made what is a relatively small mistake that led to really dire consequences. It’s incredibly tragic. It’s also fairly easy for people to avoid.”

The report said the runout angle of the avalanche was 26 degrees, though some portions of the slope were as steep as 38 degrees. According to the National Avalanche Center, avalanches are possible on any slope steeper than 30 degrees. Greene said the incident is known as a remote trigger.

“What can happen in situations like this, is that you can be walking on a fairly low-angle or even flat slope and you trigger an avalanche on steep terrain above you,” Greene said. “That’s essentially what happened to these folks. They did wander off the road, but they were still on fairly low-angle terrain, like 10 degrees.”

Greene said preparation is important so that people give dangerous areas a wide berth.

“It’s really pretty sad because we don’t see times every year where you can trigger and avalanche from a road like that,” Green said. “But we do see them in Colorado. We’ve seen them in the last two years pretty frequently.”

There are gentle slopes above the road near the trailhead at Hoosier Pass. As the road winds around to the north, it enters avalanche terrain as it crosses below a steep slope.
Colorado Avalanche Information Center/Courtesy photo

There were no witnesses to the avalanche, so the center had to gather information from the snowshoers’ tracks and discussions with their friends. From the interviews, the center reported that neither of the victims had avalanche safety training or had taken an avalanche awareness class. And they weren’t carrying an avalanche rescue equipment. However, Greene said it’s impossible to know how much planning was done just between the couple.

“Part of what we’re trying to do with these reports is construct a data set of human involvement and avalanches for researchers so they can look for trends and long-term patterns that you may not see with individual accidents,” Greene said. “One of the things we collect is if people read the (avalanche) forecast. Obviously in this case, we can’t say. We don’t know.”

The avalanche danger was rated considerable (3 out of 5) in the Summit County area on the day the snowshoers died.

Along with checking the avalanche forecast, Greene said education and recognizing avalanche terrain could have saved the pair’s lives. Greene said the area has avalanches somewhat frequently but not typically as big as what happened in this incident.

Proper education also could have led the two to snowshoe further apart. If they were traveling one at a time through dangerous terrain, the report stated that the remaining person could have conducted a rescue if the other was caught in an avalanche.

According to the report, there was an avalanche cycle in Colorado that began Dec. 23 and continued into 2022. The center documented 134 avalanches in the Vail and Summit County zone during the cycle, including 29 human-triggered avalanches. Of those 29, most occurred near and below tree line on north through east to southeast aspects. The fatal avalanche was triggered near tree line on an east-facing slope.

“The important thing to try to get across to people is that going out to take your dog for a walk and snowshoeing in the mountains is absolutely something that everybody should do, but every time that you’re going into the mountains in the wintertime, you need to think a little bit about avalanches,” Greene said.

The avalanche center recently launched a new tool on its website to help users understand avalanche activity.

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