It is up to 25 km (16 mi) wide, if measured peak-to-peak, and varies in valley relief, but is clearly visible by air and satellite/remote sensing and is easily discernible to those ascending any of the mountains or ridges lining it.

The Kootenai River, however, does not fully follow the Trench but exits Canada southwest via Lake Koocanusa reservoir to the Libby Dam.

The visible expression of the two trenches is lost where they plunge under the boreal forests of the Liard Plain proximate to the small communities of Watson Lake, Yukon and Lower Post, BC.

Right-lateral strike-slip movement of the Tintina Fault on the Tintina-Northern Rocky Mountain Trench may have begun during the middle Jurassic.

The Trench here remains mostly wild, and the northern 300 km (190 mi) is essentially without roads, excepting a few cat trails for fire, outfitters, or logging.

However, with changes in the terrain caused by beaver dams or forest fires, and despite maintenance by guide-outfitters, the trail from Fox Lake north is often hard to find, or obliterated to all but indigenous and experienced Kaska natives.

The northern trench from the Highway 97 bridge on the Parsnip River has routes on both sides of Williston Lake to Fort Ware.

The Kaska Dena culture of Fort Ware and Lower Post refer to their ancestral use of the 300 km (190 mi) natural route as The Trail of The Ancient Ones.

They also call it the Davie Trail honoring David Braconnier, the founding chief of the community at Ware (Fort Ware - originally called Kwadacha which the HBC named Whitewater Post) 1797 - John Finlay records the forks of the Finlay and Parsnip Rivers and ventures part way up each river.

[1] 1831 - John Macleod of the HBC records the mouth of the Kechika River emptying out of the northern end of the Trench into the Liard near the BC-Yukon border.

1897 to 1898 – The Canadian government sends a police patrol under Inspector Moodie to map a possible supply route from the Peace River to the Yukon - specifically Dawson City.

(Yukon Archives) 1898 – McGregor's book The Klondike Rush Though Edmonton summarizes various sources (papers) saying up to 45 parties were reported along the route from Fox River to Sylvestre's Landing.

1907 - British Columbia Premier R. McBride intervened and asked Canada to direct the police resources to connect with the more westerly Telegraph Trail route.

1912 - British Columbia Magazine - prospector Bower reports Sifton Pass as the most eventual and most practicable for a railway form the Fraser River to the Yukon.

While his advance scouts arrive at McDame Post near Good Hope Lake, the leader and entourage abandon their mission at Driftpile Creek due to fatigue, lack of horse feed, and impending winter.

Canada's Major Charles presents drawings for the Northern Trench portion of a railway from Ware to Lower Post of 351.6 km (218.5 mi), $112,000,000 cost, with 17,000 personnel over 400 days.

1964 - US Congress tables the NAWAPA proposal by Parsons Engineering Group - would see flooding of the portions of the Trench as part of a continental-scale water diversion.

1999 - Karsten Heuer completes the final section of the Y2Y hike (Yellowstone to Yukon) at Lower Post [4] 2000 - Extension of the Muskwa-Kechika Management Area into the Northern Trench.

Significant exposure is given to the M-KMA in the November 2008 National Geographic Magazine as a follow-up to their partial funding of a recent expedition to Gataga Pass.

Discussions among feasibility experts still do not seem to favor the B Route despite it being lower, more direct, fewer major river crossings and considerably less snow.

During late Paleozoic to Mesozoic time, rapid sediment deposition and subsidence to the west transitioned in the area of the modern Rocky Mountain Trench into a stable continental shelf in the east.

The Nevadan Orogeny destroyed the western wedge of sedimentary rocks during Jurassic to middle Cretaceous time, thrusting them up into metamorphic fold belts.

Currently, strata on either side of the Southern Rocky Mountain Trench consist mainly of Precambrian and Paleozoic metasedimentary and sedimentary rocks.

West of Donald BC, the Beaver river flows in from the south - but it represents the intersection of the lesser but impressive feature called the Purcell Trench.

The Canadian Pacific Railway (CPR) also constructed a spur line which extends northward up the southern Trench between Cranbrook and Golden.

These destinations include Fairmont, Panorama, Kimberley, Purden, Kicking Horse and the original Bugaboo heli-ski lodge.

The summer sports of golf, boating, fishing, and hiking round out the appeal to a growing weekend and permanent recreational population.

The generous mix of low elevation, good climate, fine scenery, diverse recreation and resort accommodation has fostered a vacation-based real estate industry for communities and rural areas surrounding Cranbrook, Windermere, Invermere, Radium, and Golden.