Reid Glacier is an

alpine glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as ...

located on the west slope of Mount Hood in the U.S. state of

Oregon Oregon () is a state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idaho. T ...

. It ranges in elevation from about . The glacier is the source of the Sandy River. The upper extent of the glacier is known for extensive

crevasse A crevasse is a deep crack, that forms in a glacier or ice sheet that can be a few inches across to over 40 feet. Crevasses form as a result of the movement and resulting stress associated with the shear stress generated when two semi-rigid pie ...

s. The glacier is a remnant of the massive glaciers that formed during the last

ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gre ...

. It is bounded on the north by Yokum Ridge which also defines the southern side of

Sandy Glacier Sandy Glacier is an alpine glacier located on the west slope of Mount Hood in the U.S. state of Oregon. It extends in elevation from about . The glacier is the source of Muddy Fork, a tributary of the Sandy River. The upper extent of the gl ...

, and by a ridge on the south bounding the north side of

Zigzag Glacier Zigzag Glacier is an alpine glacier located on the upper southwest slopes of Mount Hood in the U.S. state of Oregon. It ranges in elevation from with fingers in canyons extending to about , and lies almost entirely within Mount Hood Wilderness. ...

. The eastern and upper reaches of this ridge include Illumination Rock. The uppermost portion of the glacier is below Leuthold

Couloir A ''couloir'' (, "passage" or "corridor") is a narrow gully with a steep gradient in a mountainous terrain.Whittow, John (1984). ''Dictionary of Physical Geography''. London: Penguin, p. 121. . Geology A couloir may be a seam, scar, or fissu ...

. The glacier lies entirely within

Mount Hood Wilderness The Mount Hood Wilderness is a protected wilderness area inside the Mount Hood National Forest, in the U.S. state of Oregon. The area, covering , includes the peak of Mount Hood and its upper slopes, and ranges from temperate rain forests at the ...

. Between 1907 and 2004, Reid Glacier lost 35% of its surface area. The

glacier terminus A glacier terminus, toe, or snout, is the end of a glacier at any given point in time. Although glaciers seem motionless to the observer, in reality glaciers are in endless motion and the glacier terminus is always either advancing or retreating ...

has retreated by over the same time period.

References

Glaciers of Mount Hood Glaciers of Clackamas County, Oregon Mount Hood National Forest Glaciers of Oregon {{US-glacier-stub

See also

References