Tom Shardlow 
Mapping the Wilderness [PDF ebook] 
The Story of David Thompson

David Thompsons story is one of the great tales of North American adventure. His life was a mixture of truth and legend, but he was without a doubt one of the greatest surveyors and mapmakers of the North American continent. Raised in a charity school in London, England, and apprenticed to the Hudsons Bay Company as a teenager, he then travelled extensively, recording valuable navigational information. His life was one of adventure and hardship but also of incredible accomplishment.