Saint Mary's Glacier, Semi-permanent snowfield in Arapaho National Forest, Colorado, United States

Saint Mary's Glacier is a semi-permanent snowfield in the Arapaho National Forest that persists year-round at high elevation. The trail winds through forest and leads to an alpine lake surrounded by rocky mountain faces and open slopes.

The site was initially classified as a glacier but was later reclassified as a semi-permanent snowfield based on its stationary nature. This change reflected scientific understanding that the frozen area does not move or flow like a true glacier.

The name comes from St. Mary's Lake, the alpine lake at the base of the snowfield. The area is popular for fishing and hiking, and visitors walk the 1.6-mile out-and-back trail from the parking lot in Alice through pine and aspen forest to the lake and snowfield.

The trail is accessible year-round, though sturdy footwear is essential for the uneven and rocky terrain. Snow coverage can make some sections slippery in warmer months, so visitors should gauge their fitness level and prepare accordingly for the elevation gain.

The snowfield persists at an elevation where most surrounding mountain areas become snow-free during summer. This allows visitors to experience a frozen landscape even during the warmer months of the year.