300 glaciers have disappeared from the American West since the mid-20th century – the survivors have a few things in common

A recent study reveals that 300 glaciers have vanished from the American West since the mid-20th century, with the remaining glaciers sharing some common characteristics. Scientists have discovered that most of the surviving glaciers are small and located in topographically protected areas, which help insulate them from the changing regional climate.

The average glacier area in the Lower 48 states is about one-tenth of a square mile, while the largest glacier on Mount Rainier in Washington measures approximately 4.3 square miles. Shaded niches on the landscape provide a respite from direct sunlight, allowing these glaciers to accumulate additional snow and survive. In Montana's Beartooth-Absaroka Mountains, glaciers are thinning at a rate of 1.5 feet per year, making them the fastest-thinning glaciers in the Rocky Mountains.

Washington's glaciers, particularly those on Mount Rainier and Mount Baker, are larger and have cooler summers with more snowfall, resulting in a slower rate of ice loss. By 2100, the glaciers in Washington and the Olympics may disappear due to their proximity to the Pacific Ocean and relatively low elevation. These glaciers are crucial for providing water to high alpine ecosystems and contributing to hydropower production during the dry summer months.