The Mackenzie Highway is designated as part of Canada's National Highway System, holding core route status from its terminus at Grimshaw to its intersection with the Yellowknife Highway, and northern/remote route status for the remainder of the route to its northern terminus at Wrigley. Originally begun in 1938, prior to World War II, the project was abandoned at the outbreak of war, then resumed in the late 1940s and completed to Hay River, Northwest Territories in 1948/1949, though some sections, particularly in the vicinity of Steen River, remained difficult. In 1960, it was extended from Enterprise, approximately south of Hay River, to the northwest, then north past Fort Providence to Behchoko and southeast to the City ofYellowknife, which became the capital of the Northwest Territories in 1967. Much of this extension is now known as Northwest Territories Highway 3, the Yellowknife Highway. The stretch from Enterprise to Hay River is Northwest Territories Highway 2. In approximately 1970, the highway was extended west from what is now the southern terminus of Highway 3 to reach Fort Simpson, and in 1971, when the section to Fort Simpson was opened to traffic, work began to prepare a road grade from there to Wrigley, but the work was abandoned. This roadway, which starts at a junction from the island that "downtown" Fort Simpson is situated on, was finally made usable in 1994, and includes the N'dulee ferry and ice crossings. On November 8th 2013, the portion of the highway from the Alberta/Northwest Territories border to Enterprise was designated the Highway of Heroes. There are social and economic studies being done on the extension of the highway north from Wrigley to join the Dempster Highway; the N.W.T. government has completed 34 bridges across all but six of the widest river crossings, serving the ice road and awaiting the all-weather route. In June 2018, an announcement of $140 million funding would result in a bridge over Great Bear River and extend the Mackenzie Highway's all-weather road north by 15 km to Mount Gaudet. Just east of Fort Simpson's airport, the highway crosses the Liard River by ferry and ice bridge. further east of this crossing, the location known as Checkpoint is the site of a former gas station at the junction with the Liard Highway from Fort Nelson, British Columbia.
