Gorgeous Rock Glaciers Can Be Found in Colorado
When envisioning a glacier, the first image that comes to mind might be a large, icy mass in the middle of the Arctic Ocean. But some of the world's most spectacular rock glaciers can actually be found right here in Colorado - 3,500 of them to be exact!
According to Geology.com, a rock glacier is a mass of rock, ice, snow, mud, and water that moves slowly down a mountain under the influence of gravity. Unlike an ice glacier, rock glaciers usually have very little ice visible at the surface.
Thousands of years ago, glaciers covered many of Colorado mountain ranges, and there were even a few small ice caps. Fast forward to modern times and small reminders of those once-major masses are all that's left in the Centennial State.
Colorado's fourteen named glaciers can all be found in the Front Range, predominately in Rocky Mountain National Park. However, additional remaining small glaciers, as well as permanent icefields and snowfields, are located in other places across the state too. The six other regions containing Colorado’s glaciers are the Gore Range, Park Range, Sawatch Range, Tenmile-Mosquito Range, Medicine Bow Mountains, and in the San Miguel Mountains.
The glaciers of Colorado were not recognized until late in the nineteenth century. In 1887, G.S. Stone of Colorado Springs documented Hallett Glacier (now known as Rowe Glacier) and further provided an official scientific description. Stone described the sight in Rocky Mountain National Park as:
"The material of the ice-field, though somewhat granular on the surface, is not a mass of snow, but a clear and compact ice. ... The lower parts of the crevasses were filled with snow and broken icicles, ice stalagmites, etc., so that only from twenty to thirty feet can be seen. How much deeper the crevasses really are, is not known; but, from the size and shape of the ice-field, it does not seem probable that the greatest depth of ice exceeds fifty or seventy-five feet."
In the early twentieth century, more glaciers were identified in Colorado. A Front Range ice mass, known as Arapaho Glacier, was first discovered and written about in 1900. Measuring 0.24 km2 Arapaho Glacier is still considered to be the largest glacier in Colorado.
Scientists who have spent time studying in Colorado explain that most of the glaciers and snowfields of the Front Range occur in cirques on the east side of ridges. Andrews Glacier is a prime example of this.
In addition to Andrews, Arapaho, and Rowe, other named glacial patches located in the Front Range region are the Tyndall Glacier, Fair Glacier, and Taylor Glacier.
St. Mary's Glacier is another remnant of the past. This stunning sight can be seen in the James Peak Wilderness area. The semi-permanent snowfield is a popular seasonal hike and locals also love to cross-country ski to the breathtaking destination. The 2.4-mile out-and-back trail is rated as moderately challenging with an elevation gain of 1,030 feet, but is well worth the trek once reaching the glacier. St. Mary's is the southernmost glacier in the state.
Inside Brainard Lake Recreation Area, Coloradans can take an 8.4-mile-roundtrip adventure to Isabelle Glacier. The loop has an elevation gain of 1,355.00 feet and offers an up-close look at one of the most gorgeous glaciers in the state. During the summer, waterfalls can be heard and sometimes seen flowing from the glacier's crevices. Hikers and snowshoers can even stop and have a picnic next to the beautiful Isabelle Glacier before heading back down.
It can be hazardous to cross rock glaciers and outdoor recreationists should use extreme caution when attempting to do so. Rocks resting on ice can slide suddenly and quickly, making the terrain incredibly unsteady.
The ice masses of a rock glacier grow from precipitation, local runoff, avalanches, and spring discharge. On the opposite side of the spectrum, the sun causes ice chunks or snow present on the surface of rock glaciers to melt, which is becoming increasingly more common in a world that's constantly getting warmer. According to Colorado State University, rock glaciers are climate-resistant, but they are not climate-immune.
Colorado's glaciers are unique alpine ecosystems that provide homes for numerous plant and wildlife species, including the American pika, stoneflies, and other small mammals.