Rocky Mountain Trench

Rocky Mountain Trench is a great valley extending 1400 km NW through BC from Montana to the Liard Plain just S of the Yukon Territory. Its floor is 3-20 km wide and 600-1000 m in elevation. The trench is mainly demarcated by the wall-like slopes of major mountain ranges - the ROCKY MTS on the E and the COLUMBIA, Omineca and CASSIAR mountains on the W. The northern half of the trench is very straight and trends more northerly than the southern half, which is slightly sinuous to arcuate. Prior to construction of hydroelectric dams in eastern BC and NW Montana, 7 major rivers occupied different parts of the trench. Now all but the Fraser and Kechika empty into reservoirs (eg, WILLISTON LK) covering large areas of the valley floor. The trench is bordered along much of its length by faults and is an ancient zone of crustal weakness, perhaps a former continental margin. Its present form is a product of faulting and of erosion and deposition by rivers and glaciers during the Cenozoic period.

The southern trench is an important transportation and communication corridor and a popular tourist and recreation area. Mining, forestry and agriculture are important sources of employment. Numerous towns and settlements dot the area, the largest being CRANBROOK, KIMBERLEY and GOLDEN. Archaeological surveys have shown that Indians have inhabited the trench for thousands of years. The first NWC explorers and trappers came into the region in the late 18th century, followed by settlers of European stock. The discovery of placer gold in the Kootenay Valley in 1864, the completion of the CPR main line (1885) and the opening of the Sullivan Mine at Kimberley (1910) helped spur population growth in the southern trench, as have recent economic diversification and improvements in the road system. The northern trench remains largely undeveloped and sparsely inhabited.

Author JOHN J. CLAGUE

Links to Other Sites
Kootenay National Park of Canada
This illustrated Parks Canada website describes the ecology, geography, and history of Kootenay National Park of Canada

Southern Rocky Mountain Trench
A description of the Rocky Mountain Trench from the Rocky Mountain Trench Society website.

Northern Wetbelt Forests of British Columbia
An impressive gallery of images depicting flora and fauna of BC forests. A website from the University of Northern British Columbia.

Rockies Mystery Solved by New Mountain-Creation Theory?
A news story about alternate theories regarding geological events that may have been responsible for the formation of the Rocky Mountains. From the National Geographic website.