Printing specific areas of a topagraphical map or creating custom maps has many uses in Scouting. Canoe trips, backpacking, hiking, orienteering, and Scout camps are just some ideas.
Scans of the Canadian topographical maps, 1:50,000, can be downloaded from Natural Resources Canada.
Ontario base map vector data, 1:10,000, can be downloaded from the Geography Network. This is used with the free map making software from Map Maker to create your own custom maps with optional overlays (e.g. trails, campsites).
Finally, printable maps can be obtained from the Ontario Ministry of Northern Development and Mines Claim Maps.
Finally, the excellent, large scale, waterproof Adventure maps can be purchased from Chrismar.