Mount Rainer, which forms the heart of Mount Rainier National Park, WA, is a dormant volcano in the Cascade Range. The mountain has been carved by many glaciers. George Vancouver sighted the mountain in 1792 and named it for fellow navigator Peter Rainier. Volcanism in the Cascade Range has made it a center for geologic study. Mount Rainer is the highest peak in the range, rising to 14,410 feet (4,392 m).