Lupfer Glacier is a small glacier in Montana’s Glacier National Park, immediately east of Mount Phillips, at an elevation of about 6,000 to 6,500 feet. Covering roughly 16 acres, it falls below the 25-acre size often used as the minimum for an active glacier. Its modern history mirrors the wider loss of ice across the park: from 1966 to 2005, it shrank by more than half in surface area, making it part of the broader retreat of glaciers in this landscape.