Outpost Magazine (March/April 2007 issue) has a great article about one of Canada’s great treks: the Canol Heritage Trail in the NWT. This 355km trek along an old WWII road/pipeline is not for the faint of heart: if involves several major river crossings, and you aren’t likely to see anone (other than some big grizzlies) along the way. In 2006 only three parties completed the trip. One more reason to take on the challenge.
Some resource sites:

NWT Tourism and Parks
Backpacking the Canol Heritage Trail
Canol Heritage Trail site