Harrison Glacier

Harrison Glacier, on a southeast-facing ridge just south of Mount Jackson in Glacier National Park, is the park’s largest remaining glacier. In 2005, it covered an estimated 466 acres, or about 1.89 square kilometers. Like the park’s other glaciers, it has thinned and retreated under long-term warming, as seen in photographs from 1913 and 2009. Yet its decline has been comparatively slow: from 1966 to 2005, it lost about 9 percent of its surface area. Its high accumulation zone, around 9,000 feet, helps preserve a better balance between winter snowfall and summer melt, making it a likely survivor beyond predictions that all the park’s glaciers could vanish by 2030.

West Glacier, Montana · United States