Lava Glacier occupies the north slopes of Mount Adams, a large stratovolcano in Washington’s Gifford Pinchot National Forest, descending from about 10,000 feet to a terminus near 7,800 feet. Harry Fielding Reid named it in 1901 while surveying Mount Adams’ glaciers with C. E. Rusk. In the modern era, the glacier has undergone major change: it has generally retreated for more than a century, and from 1904 to 2006 it lost 74 percent of its surface area. Its shrinkage on one of the state’s highest volcanoes makes it a clear example of the broader retreat of Cascade Range mountain glaciers.