Terrain: The MacKenzie Mountains are a northern extension of the Rocky Mountains. The mountains and broad plateau are composed of limestone land of. The wide sweeping valleys of the Mackenzie and Liard rivers cut through this region. Rivers slice through the extensive high plateau and mountains, carving deep canyons. Those of the South Nahanni River are best known, but similar breathtaking canyons are found along other rivers in this region. Dense boreal forests of white and black spruce, with stands of jack-pine or lodgepole pine, cover the rolling uplands and terraces above the Mackenzie and Liard river valleys. Extensive areas of alpine tundra are found throughout this region. History: Named for Sir Alexander Mackenzie, who explored the Mackenzie River in 1789. Until the Second World War these mountains; they remained the preserve of the Yukon natives and the wild animals they hunted and trapped. Travel meant arduous trips by dog-team and snow-shoe in winter; in summer progress by the rivers entailed much exhausting portage. Only a handful of people pushed deep in among the ridges and valleys that fall away from a 1500-2500 m plateau and its summits.
The mountains were generally ignored until World War II when the completion of the Alaska Highway opened up this remote, jagged corner of Canada. Concurrently an oil field was developed at Norman Wells on the Mackenzie River, and a 650-km pipeline was built to Whitehorse to fuel U.S. military bases in the Pacific Northwest. After the war, oil production was confined to local needs and eventually stopped.
The oil pipeline and access road - the Canol highway - were laid through the very heart of the range, past the snow-clad summit of Keele Peak (2972 m), across untrodden rock and alternately frozen and sodden muskeg. Later, road builders pushed through 500 km of mountains from the Alaska Highway to the base-metal deposits of the Mayo district and then northwards to Dawson City on the Klondike. By the late 1950's, in country where winter temperatures drop to -50°C, surveyors were plotting an all-weather highway northwards from Dawson through the eastern foothills of the Mackenzie Mountains, across the oil-rich territory to the native settlement of Fort McPherson and thence northwards again to the Inuit village of Aklavik on the Mackenzie River, a little south of Canada's Arctic coast.
Airlines, too, launched freight and passenger services towards the Mackenzie Mountains; and oil companies sent helicopters to stake claims in Arctic and subarctic territory flanking a once remote mountain barrier which was suddenly no longer entirely remote or a barrier. But though the Mackenzie Mountains game preserve was established in 1938 the vast range's highland have remained largely untouched. Nahanni National Park was established in 1972 in the southern part of the range.