The geography of the North Cascades describes a range of rugged mountains in British Columbia, Canada and Washington, United States. In Canada, the range is officially named the Cascade Mountains but is commonly referred to as the Canadian Cascades.
The Fraser River and Similkameen River in British Columbia form the northern boundary of the North Cascades. On the east, the Okanogan River and the Columbia River bound the range. On the west within the United States, the foothills of the range are separated by a narrow coastal plain from Puget Sound, whereas in Canada there are few if any foothills and the range drops steeply to the floodplain of the Fraser Lowland.
The southern boundary of the North Cascades is less definite. For the purposes of this article, it will be taken as US Highway 2, running over Stevens Pass, or equivalently, the Skykomish River, Nason Creek, and the lower Wenatchee River. This roughly follows Beckey's division.[1]: 17 Sometimes the southern boundary is defined by Snoqualmie Pass and the approximate route of Interstate 90.[2]
Informally named ranges include the Coquihalla Range, which lies between the Coquihalla River and the Fraser Canyon south of an imaginary line roughly connecting Coquihalla Pass with the town of Boston Bar. The Coquihalla Range includes a group of horn-like summits known as the Anderson River Group, also known as the Llamoid Group due to conferred names such as Vicuna Peak, Yak Peak, Guanaco Peak, etc.
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Many tall waterfalls occur where meltwater from mountain glaciers drop down a headwall, which are common occurrences in the North Cascades. Many waterfalls, despite their great height, are non-notable as they are not clearly visible and often have low volume. Seahpo Peak Falls, despite its great height at nearly 2,200 feet (670 m), is an example of one of these waterfalls. A few notable exceptions do occur; Sulphide Creek Falls occurs where meltwaters from two of the largest Mount Shuksan glaciers are forced through a narrow chute over a 2,183-foot (665 m) headwall at the head of Sulphide Valley.
Painting of North Cascades Nat'l Park by Heinrich C. Berann. Aerial view of the entire park from the east, looking west. Ross Lake is in the foreground, drained by the Skagit River flowing toward Puget Sound and the Strait of Juan de Fuca in the background. Mount Baker is prominently visible on the upper right. Mouse over the picture and click on an area of interest.
