Tatshenshini River - This river trip is a permit only trip for more info go here http://www.env.gov.bc.ca/bcparks/explore/parkpgs/tatshens/
you will need to with US parks and pay a fee to BC parks and possibly Yukon Parks as well. Its worth it though. The river and scenerey are totally worth it . In Canada you have canyons and rapids, and as you get closer to the US the terrain opens up and you'll see glaciers everywhere you look.