Scarce map of Canada, extending west to the Rocky Mountains and the MacKenzier River.
Perhaps the most interesting feature is the depiction of the headwaters of the Missouri River. Here, the map incorporates the reports of Peter Fidler for the Hudson's Bay Company, by including a series of possible river courses to the west, leading to (and prospectively through) the Rocky Mountains. It was this section of the map that provided the best depiction of the prospect of a water route or portage through the Rocky Mountains and to the Pacific. It was this information, along with reports from local Indians encountered on the expedition, which Lewis & Clark relied in choosing their path to the Rocky Mountains.