The Rocky Mountains rise from the dense forests of central Mexico and run north through the U.S. states of New Mexico, Colorado, Wyoming, and Montana. Continuing north across the 49th parallel (the U.S.–Canada border), the range forms a natural border between the Canadian provinces of British Columbia and Alberta.
Mountainous British Columbia is Canada’s westernmost province, extending to the Pacific Ocean, while Alberta, to the east, is mostly prairie. The provincial boundary is the Continental Divide, an imaginary line that runs along the Rockies’ highest peaks. Although it is a subjective matter, perhaps most would agree that this particular stretch of the Rocky Mountains—the Canadian Rockies—is the most spectacular segment. North of British Columbia and Alberta, the Rockies descend to their northern terminus in the boreal forests of northern Canada.
The Canadian Rockies are relatively low compared to other mountain ranges of the world; the highest peak, Mount Robson, tops out at 3,954 meters (12,970 feet). Running parallel to the mountains along their eastern edge is a series of long, rolling ridges known as the foothills. To the west is the Rocky Mountain Trench, a long, wide valley that in turn is bordered to the west by various subranges of the Columbia Mountains.
© Andrew Hempstead, from Moon Western Canada, 3rd Edition