Baby Glacier is a small body of ice in Glacier National Park, Montana, occupying a cirque on the northeast slope of Numa Peak between about 7,200 and 6,800 feet in elevation. Covering roughly 19 acres, it falls below the commonly cited 25-acre minimum for an active glacier. Measurements taken from 1966 to 2005 found that it lost about one-third of its surface area. Its decline reflects the substantial shrinkage of many of the park’s smaller glaciers over time.