Reid Glacier is an

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

located on the west slope of

Mount Hood Mount Hood, also known as Wy'east, is an active stratovolcano in the Cascade Range and is a member of the Cascade Volcanic Arc. It was formed by a subduction zone on the West Coast of the United States, Pacific Coast and rests in the Pacific N ...

in the U.S. state of

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while 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. Crevasses form as a result of the movement and resulting stress associated with the shear stress generated when two semi-rigid pieces above a plastic substrate have different rate ...

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 g ...

. 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 g ...

, 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 fissure, o ...

. 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 they are in endless Glacier#Motion, motion and the glacier terminus is always either advancing o ...

has retreated by over the same time period.

Climate

Illumination Rock lies on the upper eastern side of Reid Glacier. There is no weather station, but this climate table contains

interpolated In the mathematical field of numerical analysis, interpolation is a type of estimation, a method of constructing (finding) new data points based on the range of a discrete set of known data points. In engineering and science, one often has a n ...

data.

References

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

Climate

See also

References