The Rocky Mountains

Introduction to The Rocky Mountains

Rocky Mountains, a major mountain system in the western United States and Canada. The mountains rise abruptly from the Great Plains and extend from northern New Mexico to the Arctic Ocean in northwestern Alaska. The Rockies cross parts of Colorado, Wyoming, Utah, Idaho, Montana, and Washington in the United States and parts of Alberta, British Columbia, the Yukon Territory, and the Northwest Territories in Canada. The length of the system is about 3,300 miles (5,300 km); the width is as much as 400 miles (640 km).

The Continental Divide runs along the crest of the Rocky Mountains throughout most of their course. Rivers drain eastward to the Atlantic Ocean or Gulf of Mexico, westward to the Pacific Ocean, or northward to the Arctic Ocean. Among the rivers rising in the Rockies are the Rio Grande, Arkansas, Colorado, Snake, Missouri, Columbia, Fraser, Saskatchewan, Athabasca, Peace, Mackenzie, and Yukon.

Formation of the Rockies has taken millions of years. At the beginning a vast sea covered the area now occupied by the mountains. Sediments thousands of feet thick were laid down on the sea's floor. Successive periods followed in which the land was uplifted to great heights and then worn down again by water, wind, and ice. The present mountains are the result of an uplift in which there was great folding, faulting, and thrusting of the land. In some areas, volcanic activity aided the mountain building. During the last Ice Age, great glaciers helped carve and shape the mountains.

Four Sections of the Rockies

The Rockies are often divided into four sections—Southern, Middle, Northern, and Arctic Rockies.

The Southern Rockies extend from northern New Mexico to southern Wyoming as nearly parallel north-south ranges. Separating the ranges are high valleys and broad basins, some of which are called parks. Among the principal mountain ranges are the Sangre de Cristo and San Juan mountains in New Mexico and Colorado; the Sawatch, Front, and Park ranges in Colorado; and the Medicine Bow Mountains in Colorado and Wyoming.

The Southern Rockies contain the loftiest peaks in the entire system. Colorado's Mount Elbert in the Sawatch Range, reaching 14,433 feet (4,399 m), is the highest. More than 55 other peaks, all of them in Colorado, exceed 14,000 feet (4,267 m).

The Middle Rockies begin at the Wyoming Basin, a western pocket of the Great Plains, and lie mainly in parts of Utah, Idaho, and Wyoming. Extending in many directions, the ranges are scattered and present no solid front on the Great Plains. The chief ranges include the Snowy, Absaroka, Teton, and Wind River ranges and the Bighorn Mountains in Wyoming and the Wasatch Range and Uinta Mountains in Utah. Wyoming's Gannett Peak, 13,804 feet (4,207 m), is the highest mountain.

The Northern Rockies extend northwestward from Montana, Idaho, and Washington for more than 900 miles (1,450 km) into Canada. The largest of the many ranges in the United States section include the Clearwater, Salmon River, and Sawtooth mountains in Idaho and the Bitterroot Range along the Idaho-Montana border.

In Canada the Rockies rise abruptly from the Great Plains. They have been heavily glaciated, and many sections are extremely rugged and scenic. Snow fields and glaciers still exist in some areas. Mount Robson, a 12,972-foot (3,954 m) peak in British Columbia, is the highest point in the Northern Rockies. West of the Canadian Rockies, and running parallel to them, is the Rocky Mountain Trench, a deep valley with steep walls. West of the trench rise the Purcell, Selkirk, and Monashee mountains, collectively known as the Columbia Mountains. The Cassiar and Stikine mountains, in the north, join the Arctic Rockies.

The Arctic Rockies begin in northern British Columbia, run northwestward, then westward, and end at the Arctic Ocean in northwestern Alaska. The mountains are a series of relatively low and disconnected ranges, the chief ones being the Mackenzie and Richardson mountains along the Northwest-Yukon territories boundary and the Brooks Range in Alaska.

The Wealth of the Rockies

Since the gold rushes of pioneer days, the Rockies have yielded large amounts of minerals, especially metals. Some of the world's largest mining centers dot the mountains. Copper, gold, lead, silver, uranium, and zinc are the principal metals mined. Manganese, mercury, molybdenum, and tungsten are produced in smaller amounts. Oil, coal, and phosphate rock are the chief non-metals. There are also large reserves of oil shale and low-grade coal.

Timber resources are enormous in the Rockies, and much lumber is produced. Evergreen trees, including pines, spruces, firs, larches, hemlocks, and cedars, make up much of the forests. The federal government, with more than 40 national forests, controls most of the forested land in the American Rockies. Rushing mountain rivers have been harnessed to develop electricity for industry and homes in many areas. Mountain valleys, basins, and low slopes provide rich pastures for millions of sheep and cattle. In some areas irrigation has increased the production of many crops.

The resort and tourist industry in the Rockies is of great importance. Visitors are attracted by the majestic mountains, healthful climate, and winter and summer sports and recreation. National parks offer the finest mountain scenery. Rocky Mountain, Grand Teton, and Yellowstone national parks are in the United States. Waterton Lakes, Kootenay, Yoho, Mount Revelstoke, Banff, and Jasper national parks are in Canada. Both countries have parks named Glacier National Park.