Scarce post-Lewis & Clark map of Canada, Alaska and the NW United States, from his rare General Atlas, first issued in 1828. The map includes rich details in Russian Territory (Alaska) and Canada, including one of the most detailed looks a the various trading houses and fur depot's of the Hudson's Bay Company to appear on a map, with well over 30 trading houses and early British Forts named. Portages, Indian Villages and a host of other details appear. An essential map for regional collectors. A bit of offsetting, as usual, and fold split entering 1.5 inches into the printed image.