There is a great article in WB #208 (June 2009) about canoeing on the MacKenzie in a 22' X 5' Chestnut freighter wood and canvas canoe the author bought for $100. Interestingly, their first trip was to look for Beluga whales in Shallow Bay at the delta.
Later they put the canoe on a barge and shipped it up-river to Great Slave Lake and cruised back down to Inuvik. Even though they had a 25 HP 4-stroke motor they could not keep pace with the rivers first European explorer way back in 1789, Sir Alexander MacKenzie.
The canoe could do 20 mph, and had a carrying capacity of 5000 lb. Made from 3/8" white cedar planking over 1/2" X 3" white cedar ribs and covered with #4 canvas. One of the biggest challenges was the head winds coming upstream and creating quite large (6') waves. They had a fuel line adaptation that allowed them to exchange 5 gallon gerry cans without shutting of the motor.