I've started researching the Mississippi River, its distances between major cities and time. The idea of taking a canoe the entire length is intriguing, following a water course for several months, human powered. This guy did it, and posted a great resource:
The river is about 2311 miles long. He started on August 15, 2001, and finished in the Gulf on Oct 21, averaging 34 miles a day.
Turns out, the same year Buck Nelson did this river trip, he thru hiked the AT. See that info on the same website:
This page has a bunch of stuff on Alaska hunting and hiking, books available by different authors. Never know what a person will run across looking up an unrelated topic.