The Continental Divide begins at Cape Prince of Wales, Alaska, the westernmost point on the mainland of the Americas. The Divide crosses northern Alaska into the Yukon, then zig-zags south into British Columbia via the Cassiar Mountains and Omineca Mountains and northern Nechako Plateau to Summit Lake, north of the city of Prince George and just south of the community of McLeod Lake. From there the Divide traverses the McGregor Plateau to the spine of the Rockies, following the crest of the Canadian Rockies southeast to the 120th meridian west, from there forming the boundary between southern British Columbia and southern Alberta.