About
Just outside of Idaho Springs, Colorado—over 10,000 feet above sea level—lies a pristine alpine lake. While Saint Mary’s Lake is beautiful, most visitors to this area are looking for something a little bit further up the trail: a small, somewhat dirty patch of snow, known as Saint Mary’s Glacier. Despite its name, it isn't a glacier at all.
A true glacier is defined as a mass of ice and rock that moves downhill under its own weight. While slow, they are also very powerful, stripping away the earth beneath them and shaping the landscape over thousands of years. Saint Mary’s Glacier lies inside a couloir, a small valley created by a real glacier. However, the snow patch currently occupying the couloir isn’t heavy enough to move anywhere. It also fails to meet the minimum size requirement of about 25 acres. As a result, Saint Mary’s is best classified as a permanent snowfield.
Colorado only has a handful of true glaciers left, all of which are rapidly diminishing. Rocky Mountain National Park is home to most of the remaining Colorado glaciers. While Saint Mary’s is not technically a glacier, it is still a beautiful hiking destination.
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Know Before You Go
There is a $20 fee to park. Self-serve permit stations are available at both trailheads.
The lake beneath the snowfield it is frequented by families of moose. If you do see moose at Saint Mary’s, do not approach them. While they are vegetarians, they are still very violent animals who often charge people, even while unprovoked.
Published
March 12, 2025
