Grinnell Glacier lies in the Many Glacier region of Glacier National Park in northwestern Montana, on the north flank of Mount Gould in the Lewis Range at about 7,000 feet. Named for conservationist and explorer George Bird Grinnell, it has long been one of the park’s most photographed ice features, and those images document dramatic shrinkage since the mid-19th century. Its area declined from about 710 acres in 1850, including the then-attached Salamander Glacier, to 220 acres by 1993; between 1966 and 2005 alone it lost almost 40 percent of its acreage. It remains both a popular hiking destination and a vivid sign of the park’s broader glacier retreat.