The Mackenzie Highway is a Canadian highway in northern Alberta and the Northwest Territories. It begins as Alberta Highway 2 at Mile Zero in Grimshaw, Alberta. After the first 5.0 km (3.1 mi), it becomes Alberta Highway 35 for the balance of its length through Alberta and then becomes Northwest Territories Highway 1.
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 1949, though some sections, particularly in the vicinity of Steen River, remained difficult.
In 1960, it was extended from Enterprise, approximately 23.6 miles (38 km) south of Hay River, to the northwest, then north past Fort Providence to Behchoko (at the time, known as Rae-Edzo) and southeast to the City of Yellowknife, the capital of the Northwest Territories. Much of this extension is now known as Northwest Territories Highway 3, the Yellowknife Highway. (The 23.6-mile (38.0 km) stretch from Enterprise to Hay River is 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 2.2 miles (3.5 km) 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.
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.
Just east of Fort Simpson's airport, the highway crosses the Liard River by ferry (summer) and ice bridge (winter). 27.9 miles (45 km) 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 (Northwest Territories Highway 7, British Columbia Highway 77) from Fort Nelson, British Columbia.
- "Discover the Peace Country – Grimshaw". Retrieved 2010-12-31.
- "Executive Summary of the Benefit Cost and Economic Impact Analysis Mackenzie Valley Highway Extension". NWT DoT. 1999. Retrieved 2011-01-06.