North Cascades National Park

Geography
Gorp.com

The Cascade Mountain range runs 500 miles from Northern California to British Columbia, but it is not until it reaches Northwest Washington that the mountains are at their most breathtaking. The Cascades are higher in other parts of the range, but nowhere are they as dramatic. Jagged, rocky peaks of up to 10,000 feet give way precipitously to near-sea level valleys; glaciers cling dizzyingly to the sides of foreboding slopes; everywhere waterfalls tumble down from the mountains, the characteristic that gave the Cascades their name.

Many millions of years ago, before it bumped into North America, this region was an itinerant land mass drifting in the Pacific Ocean. The mountain-building forces at work before and since that unification—accumulation of sediment from prehistoric seas, colliding tectonic plates, and volcanic activity—have combined to create one of the fastest growing mountain ranges in the world. Indeed, the North Cascades would be even taller if the counteracting forces of water and glaciers did not conspire to keep the mountains at more modest heights.

Still, the elevational distance from valleys to summits throughout the North Cascades can exceed 5,000 feet—a relief as great as any other range in the United States. The steep and imposing North Cascades presented a formidable barrier to early white explorers and the names they gave some of these mountains betray their dread: Mt. Terror, Mt. Challenger, Mt. Fury, Mt. Despair, Mt. Torment, Desolation Peak.

One of the most striking features of the North Cascades is the fantastic number of glaciers in the region. These mountains are home to over 300 of them—more than half of the glaciers in the contiguous United States. Glaciers are formed when more snow accumulates than melts or evaporates. The weight of this continuous buildup of snow is immense and causes the snow to compact into ice, which then slowly moves downhill. As glaciers move, they gouge and scrape the land and redefine landscapes. Mountains may appear to be in suspended animation but, like everything else, they are in a continuous state of change.

The reason the North Cascades contain such an abundance of glaciers is because Western Washington receives a lot of snow, especially in the mountains. Weather moves from west to east across North America, so clouds that pick up moisture in the nearby North Pacific must rise to get over the mountains. As clouds gain altitude the temperature drops, causing the water vapor to condense and fall to earth as rain and snow.

By the time the clouds cross into the rain shadow of the eastern side of the range, they are mostly spent and contain significantly less moisture. The average precipitation on the western slope is 280 cm. (112 in.), but the Pasayten Wilderness on the east side averages only 30 cm (12 in.).

Between the craggy peaks and the cool rivers, lush, temperate rain forests blanket the lowlands on the western side of the North Cascades. These forests, which are home to some of the nation's most extensive stands of remaining old growth, produce trees of exceptional size and age. Some Douglas firs, for example, grow to 250 feet and live up to 1,000 years.

Western slope forests also produce an astonishing quantity of vegetation. In terms of sheer plant volume, the forests of the Northwest are unbeatable; they contain more accumulated biomass than any other forests in the world.


advertisement

Sign up to Away's Travel Insider

Preview newsletter »