Cascade Range

The Cascade Range is a massive mountain system in western North America.

It stretches from southern British Columbia in Canada through Washington and Oregon into Northern California. This range forms part of the American Cordillera. The Cordillera is a nearly continuous chain of mountain ranges. It acts as a western backbone for North, Central, and South America. The Cascades consist of both non-volcanic mountains and active volcanoes. The volcanic peaks are known as the High Cascades.

These volcanoes are part of the Pacific Ocean's Ring of Fire. This is a circle of volcanoes and mountains surrounding the Pacific Ocean.

Geological processes make the High Cascades stand out from the rest of the range. These volcanoes often reach twice the height of nearby mountains. They frequently have a visual height of one mile or more above nearby crestlines. Mount Rainier in Washington is the highest peak in the entire range. The North Cascades and the Canadian Cascades are extremely rugged areas. In these northern sections, even the smaller peaks are steep and glaciated. The valleys are very low compared to the high ridges and peaks. This creates a landscape with great local relief, meaning sharp changes in elevation.

The climate of the Cascades is driven by its proximity to the Pacific Ocean. Prevailing westerly winds bring moisture toward the mountains. As this air rises over the peaks, it undergoes orographic lift. This process causes significant rain and snowfall on the western slopes. Some areas receive massive amounts of snow each year. In the winter of 1998–99, Mount Baker recorded a national record snowfall. Before that, Mount Rainier held the American record for snow accumulation in 1978. Because of this heavy snow, many High Cascade peaks stay white with ice all year.

Geography also creates a rain shadow effect on the eastern side of the range. This effect happens when the mountains block moisture from reaching the other side. As a result, the eastern slopes are much drier than the western slopes. The western slopes are densely covered with Douglas-fir and western hemlock. The drier eastern slopes feature mostly ponderosa pine. You may also find mountain hemlock and subalpine fir at higher elevations. The eastern foothills are quite arid. This area sits near the Columbia Plateau, which was formed by volcanic rock flows millions of years ago.

One major break in the mountain range is the Columbia River Gorge. This is the only major break in the Cascades within the United States.

The mountains began to rise about 7 million years ago during the late Miocene. As the range grew, the Columbia River continued to flow through the area. The river's erosion kept pace with the rising land. This process carved out the deep gorge we see today. The gorge also exposes layers of basalt that were warped and uplifted from the plateau. This river provided a vital path through the mountains for many years.

Many different groups of people have a history with these mountains. Before European exploration, First Nations tribes had their own names for the peaks. They called Mount Rainier "Tahoma" and Mount St. Helens "Louwala-Clough."

In 1792, British navigator George Vancouver explored the area. He gave many peaks English names after his officers. He named Mount Baker after Joseph Baker and Mount Hood after Admiral Samuel Hood. In 1805, the Lewis and Clark Expedition traveled through the range via the Columbia River. They were the first non-indigenous people to see Mount Adams. They also called the range the "Western Mountains."

The Cascades are also a center for volcanic activity in the United States. All eruptions in the contiguous United States over the last 200 years occurred here. Lassen Peak had eruptions from 1914 to 1921. Mount St. Helens had a very major eruption in 1980.

Minor eruptions at Mount St. Helens occurred again between 2004 and 2008. Today, the range is highly valued for conservation. It is home to many protected areas. These include Mount Rainier National Park and Crater Lake National Park. The northern half of the Pacific Crest Trail also follows the range.