Mount Hood - Glaciers

Glaciers

Mount Hood is host to twelve named glaciers or snow fields, the most visited of which is Palmer Glacier, partially within the Timberline Lodge ski area and on the most popular climbing route. The glaciers are almost exclusively above the 6,000-foot (1,800 m) level, which also is about the average tree line elevation on Mount Hood. More than 80% of the glacial surface area is above 7,000 feet (2,100 m).

The glaciers and permanent snow fields have an area of 3,331 acres (13.48 km2) and contain a volume of about 282,000 acre feet (0.348 km3). Eliot Glacier is the largest glacier by volume at 73,000 acre feet (0.090 km3), and has the thickest depth measured by ice radar at 361 feet (110 m). The largest glacier by surface area is the Coe-Ladd Glacier system at 531 acres (2.15 km2).

Glaciers and snowfields cover about 80 percent of the mountain above the 6,900-foot (2,100 m) level. The glaciers have lost an average of 34% over the 20th century (1907–2004). Glaciers on Mount Hood retreated through the first half of the 20th century, advanced or at least slowed their retreat in the 1960s and 1970s, and have since returned to a pattern of retreat. The neo-glacial maximum extents formed in the early 18th century.

During the last major glacial event between 10,000 and 29,000 years ago, glaciers reached down to the 2,300-foot (700 m) to 2,600-foot (790 m) level: a distance of 9.3 miles (15.0 km) from the summit. The retreat released considerable outwash, some of which filled and flattened the upper Hood River Valley near Parkdale and also formed Dee Flat.

Older glaciation produced moraines near Brightwood and distinctive cuts on the southeast side; they may date to 140,000 years ago.