Colorado's avalanche danger is high in the backcountry.
Skiers triggered this slide on Richmond Ridge near Aspen on Dec. 7. “It can be easy to underestimate the current potential for avalanches. Conditions are dangerous or very dangerous across most of our mountains,” reads a Dec. 7 update from CAIC. (Provided by Colorado Avalanche Information Center)

There is perhaps nothing more scenic than Colorado’s Rocky Mountains in the winter. Yet our freshly snow-capped peaks are also the most deadly in the nation.

Between the winters of 1950-51 and 2021-22, Colorado logged a stunning 312 avalanche fatalities, more than double that of the avalanche deaths in the second and third-ranking states, Alaska and Washington, combined.

While this season has only just begun, a total of 492 avalanches and the first fatality have already been recorded, according to Director Ethan Greene of the Colorado Avalanche Information Center. He says it’s a small fraction of the average 5,000 slide events recorded in the state annually, a tally he suggests might represent only about 10% of actual slides.

Although avalanches are hardly new in Colorado, a triple threat of gaps in knowledge, increased backcountry use and climate change appear to be changing the risks. Unfortunately, calculating this changing risk per person is difficult, arguably increasing the risk for everyone.

The knowledge gap

Reports show that 80% of avalanche deaths occur during risk levels marked as Considerable or Moderate. In comparison, only 20% of fatalities occur during periods of high avalanche risk. The decrease in deaths at high-risk times is primarily attributed to less backcountry use, perhaps specifically by less experienced adventurers.

However, speaking with multiple search and rescue volunteers, there appear to be vast gaps in knowledge regarding how to gauge considerable or moderate risks as designated by CAIC. Specifically, users seem to inaccurately consider these risk levels as far less dangerous than they are, leading many users to be underprepared for the seriousness of the terrain they are in — if they are aware of the sliding terrain at all. 

Combined with an overall lack of understanding of avalanches, including how they are triggered and how Colorado’s weather is less consistent than in other regions, the result has turned considerable or moderate risk days far more deadly.

Increased backcountry use

Adding to the knowledge gap, more users means more gaps in education, including not knowing if you’re at risk. For example, one lingering myth seems to be that slides primarily impact skiers. This misunderstanding could not be further from the truth, and recent avalanche incidents and deaths involving snowshoers, snowboarders, snowmobilers and even hikers mere minutes from a trailhead prove it.

Increased backcountry use is also impacting how avalanche metrics are collected and interpreted, according to Greene, making it overall more difficult to predict who, specifically, is at risk. New data challenges include needing to normalize data by increased use, determining updated estimates of how many slides still go unseen and an overall change in how increased human use equates to increased slides, given 90% of avalanche deaths are linked to human-triggered events.

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Climate change

This variable is a doozy when it comes to predicting avalanches. While there are some things we can say with certainty, there are still many unknowns. For example, climate change will impact avalanches as the magnitude and frequency of extreme events will continue to increase as climate change worsens. According to Greene, this could complicate avalanche prediction.

Determining exactly how, however, is difficult, especially as avalanche science is still relatively new and needs comparable funds for tools such as comprehensive snowpack modeling. For example, a more dry fall might shorten the avalanche season. Yet, the same drought might lead to a weaker base for more extreme events later in the season to turn more catastrophic. These unknowns add more pieces to the puzzle, making it tougher to predict risks for forecasters and users alike.


Know Before You Go

While scientists work to improve our ability to predict winter mountain risks, there are steps all backcountry users can take to decrease the likelihood of getting caught, buried or killed in an avalanche. Greg Foley, a senior Grand County Search and Rescue member, says it can be as simple as, “Get the forecast, get the gear, get the education.”

For Foley, this means starting with the free forecast and free education tools offered by CAIC, where Greene is the director, under the Know Before You Go program. The website offers avalanche risk levels by region, training videos and more. 

“What’s important is that these introductory courses are often free,” Foley says. “No cost, you can do it in your living room. But that’s entry-level to the avalanche knowledge you should have before you start skiing in avalanche terrain.”

From here, Foley suggests winter backcountry users take the appropriate level of avalanche training courses, such as AIARE 1 or 2, or similar classes offered by local gear shops. He then says to make sure you can carry and use the gear. 

Foley stresses that while teams like his are skilled for backcountry rescues in record time, companion rescue has the best chance to save lives. People buried in snow may only have 15 or 20 minutes before recovery to survive, and search teams might take 30 minutes or more depending on drive time and backcountry access. “Even with training,” he says, “we are a last resort.”

Foley’s final suggestion is to find a mentor before heading out. “Have someone who can show you the real, hands-on training. Someone experienced who can explain everything.” Of course, he adds, avoiding avalanche terrain is always the best way to prevent an accident.

Trish Zornio is a scientist, lecturer and writer who has worked at some of the nation’s top universities and hospitals. She’s an avid rock climber and was a 2020 candidate for the U.S. Senate in Colorado.

Trish Zornio

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Trish Zornio

Trish Zornio is a scientist, lecturer and writer who has worked at some of the nation's top universities and hospitals. She’s an avid rock climber and was a 2020 candidate for the U.S. Senate in Colorado.