What did Alexander Mackenzie discover?

Alexander Mackenzie was a Scottish explorer who discovered an overland route across Canada to the Pacific Ocean. His crossing in 1792 was the first east-west crossing of the North American continent made by a European north of Mexico, predating the Lewis and Clark expedition by a decade.

Mackenzie and his group made the journey by first following the Peace River to its source in the Rocky Mountains. Then, following the advice of the native tribes, they followed the Bella Coola River to the ocean. The expedition reportedly travelled over 36 miles a day for just over two years without losing a single member.