At approximately 12,000 feet on the north aspect of Peak 1 (also referred to as Tenmile Peak), we witnessed and unintentionally triggered two loose wet avalanches. Both slides originated on 30–35° slopes with saturated surface snow and prolonged sun exposure despite the aspect, likely due to ambient warming and recent overnight freeze/thaw cycles.

Both avalanches propagated downslope, pulling surface layers of wet snow and entraining additional slush and debris as they ran. While relatively slow-moving, the slides demonstrated considerable mass and traveled 200–300 vertical feet, fanning out into terrain traps below. No one was caught, and we quickly regrouped and reassessed snow conditions.

The Tenmile Range is a rugged and prominent subrange of the Colorado Rockies, located in Summit County, Colorado. Stretching roughly north to south from Frisco to Breckenridge, it includes iconic peaks such as Peak 1 through Peak 10 and connects seamlessly to the Mosquito Range to the south. Peaks range from around 12,800 to just over 13,600 feet, offering high-alpine terrain above treeline.

Started in Frisco, skinned south, then transitioned west to ascend the ridgeline dividing the north- and south-facing aspects of Peak 1 in the Tenmile Range.

Tenmile peak, North facing aspect, 12,200

After descending approximately 500 vertical feet, the snowpack transitioned rapidly from supportable and fairly firm to unsupportable slush. The upper section held up well under ski, but lower down, free water in the top layers caused the surface to become saturated and punchy, significantly increasing the likelihood of wet loose activity and making skiing more hazardous.

In our pre-trip plan, we set a firm turnaround time of 12:00 p.m., recognizing that solar radiation would make skiing unsafe beyond that point. Despite this, we underestimated conditions. The day was more overcast than forecasted, which gave us a false sense of security regarding surface stability. We reached our transition point just before noon and, based on the lingering cloud cover and timing, judged it was still early enough to proceed. In hindsight, the warming had already done its work - clouds or not - and we had pushed past our ideal window.