Point of Information Crossing the Stikine River. Photo looking east at the Stikine River. Steep-walled canyon, composed of sedimentary and volcanic rock, has been carved through years of river water erosion. In the bottom of this sometimes 300 m deep chasm flows the wild and unnavigable Stikine River, which varies in width from 200 m to as little as 2 m at a point near the Tanzilla and Stikine confluence. The Stewart-Cassiar Highway The Stewart-Cassiar Highway runs from the junction of Highway #16 (The Yellowhead Route) north to the Yukon border and connects with The Alaska Highway.This highway offers some of the most awe-inspiring scenery, with wild rivers, deep canyons and wildlife that you will encouter along the way.