Wilson Glacier lies on the east slopes of Mount Adams within the Yakama Indian Reservation, descending from about 10,600 feet to near 7,400 feet. Its name grew out of early twentieth-century exploration of the mountain’s ice. Harry Fielding Reid referred to it as Little Muddy Glacier in 1906 after surveying Mount Adams’s glaciers, while Claude Ewing Rusk later renamed it for President Woodrow Wilson. Rusk also named nearby Roosevelt Cliff for Theodore Roosevelt. Over more than a century, Wilson Glacier has generally retreated, and from 1904 to 2006 it lost 14 percent of its surface area, reflecting the long-term shrinkage of Mount Adams’s glaciers.