Colonial Peak is a mountain in the North Cascades

North Cascades

The North Cascades are a section of the Cascade Range of western North America. They span the border between the Canadian province of British Columbia and the U.S. state of Washington and are officially named in Canada as the Cascade Mountains...

 of Washington, United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. It rises steeply from the southwest bank of Thunder Arm of Diablo Lake

Diablo Lake

Diablo Lake is a reservoir in the North Cascade mountains of northern Washington state, USA. Created by Diablo Dam, the lake is located between Ross Lake and Gorge Lake on the Skagit River at an elevation of above sea level...

, one of the artificial reservoirs on the Skagit River

Skagit River

The Skagit River is a river in southwestern British Columbia in Canada and northwestern Washington in the United States, approximately 150 mi long...

. It is part of a group of peaks that form the northern end of a chain running south through prized climbing

Mountaineering

Mountaineering or mountain climbing is the sport, hobby or profession of hiking, skiing, and climbing mountains. While mountaineering began as attempts to reach the highest point of unclimbed mountains it has branched into specialisations that address different aspects of the mountain and consists...

 destinations such as Eldorado Peak

Eldorado Peak

Eldorado Peak is a peak in the North Cascades of the U.S. state of Washington, about east of Concrete. It is located in North Cascades National Park at the head of Marble Creek and west of Inspiration Glacier. Other glaciers in the immediate vicinity include Eldorado Glacier and McAllister Glacier....

, Forbidden Peak

Forbidden Peak

Forbidden Peak is part of the North Cascades and is located near Cascade Pass. Forbidden Peak features a rock climbing route named West Ridge route which is featured in Fifty Classic Climbs of North America.- External links :* . MountainProject.com....

, and Mount Goode. Colonial Peak takes its name from the Colonial mining claim on its slopes.

Like many North Cascade peaks, Colonial Peak is more notable for its large, steep rise above local terrain

Terrain

Terrain, or land relief, is the vertical and horizontal dimension of land surface. When relief is described underwater, the term bathymetry is used...

 than for its absolute elevation. For example, it rises 6,560 feet (2,000 m) above Thunder Arm in only 2.3 horizontal miles (3.7 km). Its rise over the Skagit river on the northwest is even greater, but not as steep.

Colonial Peak was first climbed on July 31, 1931 by William Degenhardt and Herbert Strandberg of the Seattle Mountaineers. The standard route is the West Ridge, accessed from Colonial Glacier; the approach is via the Pyramid Lake Trail, starting from near Diablo Dam

Diablo Dam

Diablo Dam is one of three dams along the upper Skagit River in Whatcom County, Washington and part of the Skagit River Hydroelectric Project that supplies Seattle with a large proportion of its power needs. Work was begun in 1917 on a six-mile tunnel through Diablo Canyon and subsequent...

 on the North Cascades Highway.