Rocky Mountain Trench Rivers

On my way home I had a nice view of the Rocky Mountain Trench.

Rocky Mountain Trench looking towards the north. 

The north arm of Kinbasket Lake is in the trench on the right.

The valley west of the trench is the upper Thompson River.

The Trench is a remakable feature that is about 1,000 miles long. The feaure jumps out in satelite imagery and Google Earth as the lower elevation of the trench forms a dark swath through the high snow covered mountains of the BC interior. The trench follows a major strike-slip tectonic fault, the Tintina Fault. There are other trench like feautes that are somewhat parallel, but none are as continuous. A number of major western rivers flow into and out of the trench. The river plumbing is complex and intriguing.

A few of the Trench rivers: Fraser, Canoe, Columbia and Kootenay. 

The source of the Columbia River is within the trench south of the photograph I took. Kinbasket Lake was formed in the Trench when Mica Dam was built across the location where the Columbia leaves the Trench. The north arm of Kinbasket Lake in the picure is the now flooded Canoe River. Not far north of the lake and Canoe River the Fraser River flows into the Trench and follows the Trench to the north for a long distance. Like the Columbia, the Fraser leaves the Trench and makes a U turn and heads south. I also marked the Kootenay River on the Google Erath view. The Kootenay flows into the trench from the east about 1 mile south of the Columbia source at Canal Flats, but the Kootenay heads south down the Trench whereas the Columbia flows north. Eventually the Kootenay exits the Trench and joins the Columbia.        

It is intriguing to think about how the ice ages may have rearranged the upper river systems. If we look at the current river routes one can imagine glacial ice filling the northern portion of the Trench and forcing the upper Fraser south into the Columbia. Or the Columbia being blocked by ice and flowing south down what is now the Kootenay route. I can also imagine that prior to the last glacial period the upper river routes may have differed possibly resulting in an even large Columbia or alternatively a larger Fraser.  

Returning Home with a 'View' of the BC Coast Range

 Returning home the southern portion of the BC Coast Range was obscured by low clouds; hence, I was unable to observe some of the challenging areas from past geology ventures of another work era as the plane descended towards Vancouver. One peak poked above the cloud cover.

The cloud cover was not a bad mimic of the past when the BC Coast Range was mantled with a massive ice sheet that flowed down into the lowlands into the northern Washington straits and out the Strait of Juan de Fuca and filling the Puget lowland with ice all the way to south of Olympia.