Mount Rainier visitors who enter "ice caves" are risking their lives, according to park officials.

Visitors to Mount Rainier National Park in Washington who venture into "ice caves" are risking their lives, according to park officials.

The warning comes as social media posts about entering an "ice cave" have been making the rounds, along with a video sharing information that now is a good time to “check out Mount Rainier’s ice caves.” 

The risk, though, is that the images came from a melt-water channel running beneath a perennial snowfield (snow that persists through the summer), the park said. Officials strongly discourage visitors from approaching or entering ice caves or melt water channels as they are prone to spontaneous collapse due to melting, which is accelerated this time of year. Collapse, or ice and rock fall could be fatal or cause serious injuries to those who venture inside or near the entrance.   

Those entering these channels/caves also are in danger of hypothermia due to the combination of cold air temperatures inside and colder melt water flowing from the snowfield. Melt water volumes inside will increase throughout the day (just as stream crossing hazards are greater in the afternoon).  

Mount Rainier National Park in the past was known for a few well-developed ice caves, but with the warming climate, those have disappeared, replaced only by transitory and unstable channels/caves. The park closed the historic ice caves around 1980 due to unsafe conditions, including ice chunks and flakes, some the size of a small car, breaking loose and falling from the cave ceiling.