Biggest Avalanche in Rocky Mountain National Park, What We Know
The phrase “biggest avalanche” gets tossed around a lot in Rocky Mountain National Park. The terrain looks dramatic, the snow stacks up fast, and popular routes cut through serious avalanche paths.
But there is an important reality. There is no single public list that ranks the biggest snow avalanche inside the park. “Biggest” depends on how it is measured, and many avalanches are never formally surveyed.
So the most helpful way to answer the question is to separate three things: what is measurable, what is well documented, and what matters for your safety today.
Why it is difficult to name one “biggest” snow avalanche
Snow avalanches are not one-size events. Two slides can look similar on video and be totally different in impact.
“Biggest” might mean:
Largest volume of moving snow
Longest runout distance
Highest consequences for people or infrastructure
Most complete documentation, including photos, debris mapping, or measurements
In a wilderness setting, many large avalanches happen without anyone there to record them. That makes clean comparisons rare.
The recent RMNP avalanche caught on video near Lake Haiyaha
A recent incident highlights why this topic matters. On January 10, 2026, skiers in the Haiyaha Couloir triggered a wind slab avalanche. Video shared publicly shows two skiers caught and carried during the slide.
According to the Colorado Avalanche Information Center’s summary as reported widely, the group was ski cutting the upper chute when the wind slab released and cleared part of the slope. The reported crown depth was about 8 to 14 inches. One skier was briefly buried and dislocated a shoulder while grabbing a tree. The group managed the injury and exited safely, and no serious injuries were reported.
What this avalanche teaches, even if it was not the biggest
This was not a “headline biggest” event by size. It is still a perfect case study in consequences.
A wind slab can feel supportable one minute and fracture the next. Couloirs add another layer of risk because terrain traps amplify the outcome. Even a smaller slide can bury a person, slam them into rocks, or pin them in a narrow gully.
If you only take one lesson from the Haiyaha Couloir incident, take this: the wrong place makes any avalanche bigger.
The biggest documented “avalanche-like” slide in the park: Chaos Canyon in 2022
If you widen the definition beyond snow, the largest, best documented rapid slide event in the park in recent years is the June 28, 2022 Chaos Canyon event below Hallett Peak. It is commonly described as a rapid debris slide involving ice-rich material, not a classic snow avalanche.
It matters here because it shows what “biggest” looks like when an event is measured carefully. It also reshaped a highly visited area near Lake Haiyaha and changed conditions on the ground for years.
If your goal is a single, defensible “largest documented slide event,” this is the one people usually mean. If your goal is “biggest snow avalanche,” the record is less clear.
A historic reminder: avalanches can destroy structures in RMNP
One of the clearest historical examples of avalanche power in the park is the Chasm Meadows patrol cabin, which was destroyed by an avalanche in the spring of 2003. That location sits in serious avalanche terrain below Longs Peak, where runouts can reach into the meadows.
Even without exact volume numbers, the outcome is unambiguous. Avalanches in RMNP can be strong enough to remove buildings.
What to do with this information, practical travel guidance
If you are staying on packed, low-angle routes near trailheads, avalanche risk is often lower. Once you step into steeper terrain, bowls, couloirs, or open glades, you are in avalanche country.
A realistic baseline for winter and spring travel includes:
Check the avalanche forecast for your exact zone before leaving home
Carry beacon, shovel, and probe, and practice with them
Avoid steep wind-loaded slopes after storms or strong winds
Give extra space to terrain traps like gullies, creek beds, and couloirs
Also watch for simple red flags: cracking, collapsing, fresh avalanches, and rapid warming. Those signs do not need expert interpretation.
FAQ
Was the Haiyaha Couloir avalanche considered large?
It was widely reported as a wind slab with a modest crown depth. It was still dangerous due to the terrain.
Is there an official “biggest avalanche” record for RMNP?
Not as a single, public ranking for snow avalanches. Many events are not fully measured or compared.
When is avalanche risk highest in the park?
It can exist all winter. It often spikes after storms, wind loading, and warming trends.
Conclusion
The biggest avalanche in Rocky Mountain National Park is not a simple trivia answer. The park’s most documented massive slide event in recent years was the 2022 Chaos Canyon debris slide. For snow avalanches, the better takeaway is what the January 10, 2026 Haiyaha Couloir incident makes obvious: size is not the point, consequences are.