Gem Glacier, Glacier in Glacier National Park, Montana, United States

Gem Glacier is a hanging glacier on the east side of the Continental Divide, on the Garden Wall arête in Glacier National Park, Montana. It drapes down the north face of the steep arête, directly above the larger Grinnell Glacier, and covers only 5 acres (0.020 km²).

Between 1966 and 2005, Gem Glacier lost 30 percent of its acreage, while the neighbouring Grinnell Glacier below it lost 40 percent. Its area of about 5 acres (0.020 km2) keeps it well below the 25-acre threshold often cited for an active glacier. The glacier lies on the east, Glacier County side of the Continental Divide arête known as the Garden Wall.

Gem Glacier hangs on the Garden Wall above Grinnell Glacier, and its name follows the park's practice of naming small ice bodies for their setting rather than for size. It is the smallest glacier in Glacier National Park, covering only 5 acres, well below the 25-acre threshold often used to define an active glacier. Between 1966 and 2005 it lost 30 percent of its area, while neighbouring Grinnell Glacier lost 40 percent.

Visitors can observe this glacier from several marked viewing areas along the park's hiking trails during the warmer months. The clearest views typically come early in the day when sunlight illuminates the ice from the proper angle.

At 5 acres, Gem Glacier falls far below the 25-acre threshold often used to define an active glacier. Between 1966 and 2005 it lost 30 percent of its area, while neighbouring Grinnell Glacier lost 40 percent. It hangs on the north face of the Garden Wall arête, above Grinnell Glacier.