ROCKIES - 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.

Canadian Rockies 

The Canadian Rockies, located in south-western Alberta and eastern
British Columbia, are composed of a relatively narrow belt of mountain
ranges that terminates at the Liard River lowland in north-eastern
British Columbia. They include, in southern British Columbia, the
Purcell, Monashee, and Selkirk Mountains, and some 200 km (125 mi)
further north, the Cariboo Mountains. The peaks of the section, which
takes in Banff, Jasper, Kootenay, Waterton Lakes, and Yoho National
Parks, include Mount Robson (3,954 m/12,972 ft high), Mount Columbia
(3,747 m/12,294 ft high), and The Twins (3,734 m/12,251 ft
high). Slopes generally are very steep, and there are numerous
glaciers, most noticeably those descending from the Columbia Icefield,
astride the Continental Divide on the Alberta-British Columbia
border. With an area of some 500 sq km (200 sq mi), it is the largest
icefield of the Rockies, and its glaciers feed the Saskatchewan,
Athabasca, Fraser, and Columbia rivers.