Glaciers

The mountainous landscape of Glacier National Park was formed largely by the glaciers for which the park is named.

Plan Around Glaciers

A good stop is not just something to read about. Once it belongs on the day, move into a saved trip and build the route around it.

Add to trip View park guide

Use this detail page to confirm that the stop is worth it, then carry that decision into a trip draft while the park context is still fresh.

Glaciers Details

The mountainous landscape of Glacier National Park was formed largely by the glaciers for which the park is named. The mountains were carved into their present shapes by the glaciers of the last ice age, most of which have disappeared over the last 12,000 years. Evidence of this glacial action is found all over the park, in the form of U-shaped valleys, glacial cirques, arêtes, and large outflow lakes radiating from the base of the highest peaks. There have been various warming and cooling trends over the millennia; the most recent cooling trend during the Little Ice Age, which took place approximately between 1550 and 1850. During that time, the glaciers expanded and advanced, though not nearly as much as during the last Ice Age itself. After the Little Ice Age ended in 1850, the park's glaciers retreated moderately until the 1910s. Between 1917 and 1941, the retreat rate accelerated, and was as high as 330 feet a year for some glaciers. A slight cooling trend from the 1940s until 1979 helped to slow the rate of retreat and, in a few cases, some glaciers even advanced a bit. In 1850, the glaciers in the region near Blackfoot and Jackson Glaciers covered 5,337 acres, but by 1979, the same region of the park had glacier ice covering only 1,828 acres. Between 1850 and 1979, 73 percent of the glacial ice had melted away. By 2010 only 37 glaciers, remained although only 25 of these were considered to be "active glaciers" at least 25 acres big. If current warming trends continue, all of the remaining glaciers in the park will be gone between 2020 and 2030, depending on the rate of warming, experts predict. The impact of glacial retreat on the park's ecosystems is not yet fully known, but cold-water dependent plants and animals will certainly suffer a loss of habitat. Reduced seasonal melting of glacial ice may also affect stream flow during the dry summer and fall seasons, reducing water table levels and increasing the risk of forest fires.

Difficulty

Distance

N/A

Estimated time

Region

Learn About the Park