Rocky Mountains

I

Introduction

Rocky Mountains or Rockies, great chain of rugged mountain ranges in western North America, extending from central New Mexico, United States, to north-eastern British Columbia, Canada, a distance of about 3,220 km (2,000 mi). The Rockies are bordered on the east by the Great Plains and on the west by the Great Basin and the Rocky Mountain Trench, a plateau running from north-western Montana to northern British Columbia and separating the Rockies from parallel mountain ranges further west. The Rocky Mountains form part of the Continental Divide, which separates rivers draining into the Atlantic or Arctic oceans from those flowing towards the Pacific Ocean. The Arkansas, Colorado, Columbia, Missouri, Rio Grande, Saskatchewan, Fraser, Peace and Snake rivers rise in the Rockies.

II

Topography

A

Southern Rockies

The Rockies may be divided into four principal sections—Southern, Central, Northern, and Canadian. The Southern Rockies, which include the system's broadest and highest regions, extend from central New Mexico, through Colorado, to the Great Divide Basin, in southern Wyoming. This section is composed chiefly of two northern-southern belts of mountain ranges with several basins, or parks, between the belts. The component parts include the Sangre de Cristo and Laramie Mountains and the Front Range, in the east, and the San Juan Mountains and the Sawatch and Park ranges, in the west. The Southern Rockies include the chain's loftiest point, Mount Elbert (4,399 m/14,433 ft high), in central Colorado, and there are more than 50 other peaks rising above 4,267 m (14,000 ft) in the state; these include Longs Peak (4,345 m/14,256 ft high) and Pikes Peak (4,301 m/14,110 ft high).

B

Central Rockies

The Central Rockies are in north-eastern Utah, western Wyoming, eastern Idaho, and southern Montana. They encompass the Bighorn, Beartooth, and Uinta Mountains and the Absaroka, Wind River, Salt River, Teton, Snake River, and Wasatch ranges. The Uinta Mountains are the only major portion of the Rockies that extends east-west rather than north-south. Among the peaks of the Central Rockies, which include Grand Teton and Yellowstone national parks, are Gannett Peak (4,207 m/13,804 ft high), Grand Teton (4,197 m/13,770 ft high), and Fremont Peak (4,185 m/13,730 ft high).

C

Northern Rockies

The Northern Rockies are in northern Idaho, western Montana, and north-eastern Washington. They include the Sawtooth, Cabinet, Salmon River, and Clearwater mountains and the Bitterroot range. The loftiest points in the section, which includes Glacier National Park, are Granite Peak (3,901 m/12,799 ft high) and Borah Peak (3,859 m/12,662 ft high).