Iconic St. Mary’s Glacier has disappeared amid record-hot summer
Colorado’s iconic St. Mary’s Glacier has melted away for the first time in at least a century, a victim of rising temperatures in the high country, according to a glaciologist with Colorado State University.
For decades, the perennial patch of snow and ice (that is, in fact, not a glacier) offered a rare and accessible year-round destination near Idaho Springs for skiers and a summertime escape for visitors looking to find snow. Until now, the snowfield had remained intact for at least the last 100 summers, replenished each winter by new snowfall, according to Dan McGrath, a glaciologist and associate professor at Colorado State University.
But on Friday morning when a Colorado Sun reporter reached the valley, it was barren. A small waterfall that used to jut out from the snowfield, flowed from a pile of rocks, on its way to St. Mary’s Lake down the hill.
“It is not like we’re never going to see St. Mary’s snowfield again. Following big winters, it will exist in the summer,” McGrath told The Colorado Sun. “But I think it’s safe to say that these glaciers — and I’m using that term broadly here to encompass all these snowfields — they’re on a one-way street toward disappearing.”
2020 vs. 2026
1938 vs. 2026
Glaciers and perennial snowfields naturally grow and retreat from year to year. But after Colorado’s hottest summer on record and historically low snowpack, more snow and ice is melting than can be replaced, said McGrath, who studies glaciers across the state.
“There may be winters where there’s a couple good winters in a row and we rebuild a little bit of this snow that may consolidate to ice over time, but that’s becoming increasingly unlikely given the warming climate that we’re in,” he said.
“The savings account has essentially been drained.”
News of the St. Mary’s melting didn’t come as a surprise to McGrath who has been looking at satellite imagery of snowfields and glaciers along the Front Range all summer, knowing that their future was bleak.
Last week, McGrath, along with a CSU undergrad and a retired scientist at the National Snow and Ice Data Center in Boulder, flew over St. Mary’s snowfield to photograph the shrinking ice and snowfield from above.
“At that point you know there was this tiny little patch of debris-covered, rock-covered ice that was probably 5-feet-by-5-feet or 5-feet-by-10 feet at that time,” he said of what he saw Sept. 9. “So at that point, I knew it was inevitable.”
Historical photos of St. Mary’s show how much the snowfield has fluctuated over the years. An October 1938 image shows the snowfield intact surrounded by dry land. A large patch of snow and ice was still present even after another exceptionally dry summer in 2002, according to another historical image.
“It’s not like it’s always been this very large, plump snowfield every summer. It’s highly variable depending on how much snow falls and how much snow gets drifted, wind blown into this ravine, which is essentially what it is — it’s a steep ravine that fills with snow,” McGrath said.
The snowfield was popular because of its beauty and accessibility. The trailhead is about 30 minutes from Interstate 70 and the hike is roughly 1½ miles.
Laura Bookatz, of Denver, who was hiking with her toddler daughter Friday morning, is a frequent visitor to the St. Mary’s area. Seeing no visible snow, let alone the historic snowfield, was “sad but not surprising,” she said.
St. Mary’s also became a training ground for mountaineers learning basic ice ax and crampon techniques. The Colorado Mountain Club regularly hosts trips to the snowfield, usually during the winter.
St. Mary’s and other snowfields and glaciers around the state persist in part because of where they sit on the landscape, McGrath said. Snow can be blown into them by the wind or dumped on them by avalanches.
On Arapaho Glacier, in the Indian Peaks Wilderness west of Boulder, for example, McGrath has measured upwards of 45 feet of snow accumulating in a single winter. That isn’t all snow that fell from the sky, a lot of it was blown on to the glacier.
Colorado’s glaciers may not play the same role in the state’s water supply as glaciers do in places such as the Andes or Himalayas, but they are an important part of the state’s alpine ecosystems. They provide cold meltwater later in the summer, when little snowmelt typically remains.
“But you don’t need to get very far downstream where this impact is quite minimal,” he said.
But McGrath sees Colorado’s disappearing glaciers and snowfields as part of a much larger warning about climate change unfolding around the world. He pointed to the catastrophic floods along the Nepal-Tibet border after glacial rock and ice collapsed, killing more than 1,300 people and leaving thousands more missing.
“To me, that is a very clear signal that our mountain ranges around the world are at a tipping point and that they’re essentially becoming unglued,” he said. “That to me should be way more of a wake up call.”
Colorado Sun reporter Michael Booth contributed to this story.
