The Alaska Highway (French: Route de l'Alaska; also known as the Alaskan Highway, Alaska-Canadian Highway, or ALCAN Highway) was constructed during World War II to connect the contiguous United States to Alaska across Canada. It begins at the junction with several Canadian highways in Dawson Creek, British Columbia, and runs to Delta Junction, Alaska, via Whitehorse, Yukon. When it was completed in 1942, it was about 2,700 kilometres (1,700 mi) long, but in 2012, it was only 2,232 km (1,387 mi). This is due to the continuing reconstruction of the highway, which has rerouted and straightened many sections. The highway opened to the public in 1948. Once legendary for being a rough, challenging drive, the highway is now paved over its entire length. Its component highways are British Columbia Highway 97, Yukon Highway 1 and Alaska Route 2.

An informal system of historic mileposts developed over the years to denote major stopping points. Delta Junction, at the end of the highway, makes reference to its location at "Historic Milepost 1422". It is at this point that the Alaska Highway meets the Richardson Highway, which continues 155 km (96 mi) to the city of Fairbanks. This is often regarded, though unofficially, as the northwestern portion of the Alaska Highway, with Fairbanks at Historic Milepost 1520. Mileposts on this stretch of highway are measured from the port of Valdez on Prince William Sound, rather than the Alaska Highway. The Alaska Highway is popularly (but unofficially) considered part of the Pan-American Highway, which extends south (despite its discontinuity in Panama) to Argentina.