Little Jack is a 6,745-foot-elevation (2,056 meter) mountain summit in the North Cascades of Washington, United States. It is located within the

Pasayten Wilderness The Pasayten Wilderness is a protected area located within Okanogan–Wenatchee National Forest and Mount Baker National Forest in Washington state, centered on the Three Forks () of the Pasayten River, a tributary of the Similkameen River. Al ...

. It is situated one mile south of its namesake

Jack Mountain Jack Mountain is the 17th highest mountain in Washington state. It is one of the 10 non-volcanic peaks in Washington State over . It towers dramatically over the south end of Ross Lake, rising above the lakeshore in only . Nohokomeen Glacier ...

, west of

Crater Mountain Crater Mountain is an mountain summit located in the North Cascades of Washington state. It is the 29th highest mountain in the Pasayten Wilderness. The Jerry Glacier resides in the cirque on the upper north slopes of the mountain. The crate ...

, and east of Ross Lake. Like many North Cascade peaks, Little Jack is more notable for its large, steep rise above local terrain than for its absolute elevation. In the early 1900s, the Forest Service built the Little Jack Trail for the purpose of grazing pack animals on the meadows of Little Jack Mountain.Geology of the North Cascades: A Mountain Mosaic. by Rowland W. Tabor, Ralph Albert Haugerudme. The Mountainers publisher. 1999 The name "Jack" refers to Jack Rowley, a gold prospector in the area during the late 1800s, who was credited with finding gold at Ruby Creek.

Climate

Little Jack is located in the marine west coast climate zone of western North America. Weather fronts originating in the Pacific Ocean travel east toward the Cascade Mountains. As fronts approach the North Cascades, they are forced upward by the peaks of the Cascade Range ( orographic lift), causing them to drop their moisture in the form of rain or snow onto the Cascades. As a result, the west side of the North Cascades experiences high precipitation, especially during the winter months in the form of snowfall. Because of maritime influence, snow tends to be wet and heavy, resulting in high avalanche danger. During winter months, weather is usually cloudy, but due to high pressure systems over the Pacific Ocean that intensify during summer months, there is often little or no cloud cover during the summer. Beckey, p. 16 Precipitation

runoff Runoff, run-off or RUNOFF may refer to: * RUNOFF, the first computer text-formatting program * Runoff or run-off, another name for bleed, printing that lies beyond the edges to which a printed sheet is trimmed * Runoff or run-off, a stock market ...

from the mountain drains into the Skagit River.

Geology

The North Cascades features some of the most rugged topography in the

Cascade Range The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, ...

with craggy peaks, ridges, and deep glacial valleys. The history of the formation of the Cascade Mountains dates back millions of years ago to the late Eocene Epoch. With the North American Plate overriding the

Pacific Plate The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At , it is the largest tectonic plate. The plate first came into existence 190 million years ago, at the triple junction between the Farallon, Phoenix, and Iza ...

, episodes of volcanic igneous activity persisted. In addition, small fragments of the oceanic and continental lithosphere called terranes created the North Cascades about 50 million years ago. Little Jack Mountain is part of the ''Little Jack terrane''. Outcrops of granite and fine-grained mica schist can be found on the top of Little Jack Mountain. During the Pleistocene period dating back over two million years ago, glaciation advancing and retreating repeatedly scoured the landscape leaving deposits of rock debris. The U-shaped cross section of the river valleys is a result of recent glaciation.

Uplift Uplift may refer to: Science * Geologic uplift, a geological process ** Tectonic uplift, a geological process * Stellar uplift, the theoretical prospect of moving a stellar mass * Uplift mountains * Llano Uplift * Nemaha Uplift Business * Uplif ...

and faulting in combination with glaciation have been the dominant processes which have created the tall peaks and deep valleys of the North Cascades area.

Gallery

File:Jack Mt.jpg, Jack Mountain (left), Little Jack (right) File:Jack Mountain and Diablo Lake.jpg,

, ''Little Jack'', and

with Diablo Lake

References

{{reflist Mountains of Whatcom County, Washington Mountains of Washington (state) Cascade Range North American 2000 m summits North Cascades

Climate

Geology

Gallery

See also

References