This photo shows the snout, or terminus, of Nisqually Glacier, near the Paradise visitor area in Mt. Rainier National Park. The terminus is dark with rock debris. To the left, the gray ridge and slope of fresh, un-vegetated rock and dirt is a lateral moraine. The lateral moraine marks the neoglacial maximum (a recent advance, in Holocene time) of the glacier. Clearly the glacier has retreated a long way, in recent years, although whether it will continue to retreat is an unresolved question.

The Paradise area on the south side of Mt. Rainier is a good place to examine the glacial history of this composite cone, and a few pieces of its volcanic history. Flowers, trees and tourists reap the benefits of the geologic setting created by the volcano and the glaciers

Glacially Faceted Boulder

The boulder in this image is a glacial erratic. It was left on the ground by a retreating glacier. The erratic is faceted (flattened) and grooved, probably due to being carried at the base of the flowing ice and scraping against the ground as it was carried along in the moving glacier. A glacier has not covered this portion of Paradise since the Pleistocene epoch, approximately 10,000 years ago. Select the image to see a larger view. Use your browser's back button to return to this page.

Glacier Terminus

This is a closer view of the terminus of the Nisqually Glacier. Upon close inspection, you might be able to make out layers of ice curving down the snout of the glacier. Each layer formed from a year's worth of accumulated snow. Select the image to see a larger view. Use your browser's back button to return to this page.

This photo catches a glacier in the act of depositing glacial till, as it dumps the rock and dirt from the flowing, melting ice onto the ground. Along the bottom of the picture you can see the crest of a lateral moraine, scattered with boulders and sparsely covered by thin vegetation. This moraine formed when the glacier extended father down the valley and was thicker and higher at this point in the valley.

Columnar-Jointed Andesite

The columnar-jointed andesite shown in this photo solidified from a flow that came down the flanks of Mt. Rainier. The columns form as the flow slowly cools and shrinks, a natural way of accommodating the reduced volume of the solidifying lava. Andesite is the most common type of rock in Mt. Rainier, just as it is in nearly all composite cone volcanoes. Select the image to see a larger view. Use your browser's back button to return to this page.

Nisqually Glacier Overview

In this image you can see more of Nisqually Glacier, the Paradise visitor center (the round building), and Paradise Lodge. Most of the terrain in this picture was once glaciated, at least down to where the forest is solid with trees. Select the image to see a larger view. Use your browser's back button to return to this page.

The upper slopes of Mt. Rainer are hidden in the clouds. Because composite cones commonly build up to over 3,000 m (10,000 ft) in elevation, they cause the wind to rise up and create lots of clouds and precipitation as the weather crosses the volcano. The high annual snowfall at Mt. Rainier feeds the largest complex of glaciers in the lower 48 states. Until recently, Mt. Rainier, at Paradise, held the U.S. record for the officially measured amount of annual snowfall. That record was broken during the winter of 1999-2000 at a snow-measuring station on Mt. Baker, another composite cone of the Cascade volcanic arc.

Glossary terms that appear on this page: glacier; lateral moraine; glacial erratic; glacial till; moraine; andesite; composite cone