Mount Logan

Wet air from the ocean brings lots of snow to these mountains.

The snow piles up and turns into ice that slowly flows down as glaciers.

The St. Elias Mountains have two ranges with a narrow trough between them. The front range averages about 2,500 meters, while the Icefield Ranges behind it, where Mount Logan stands, have peaks that soar into the 5,000-meter range.

Among these peaks lies one of the world's largest icefields outside the polar regions, left from the last ice age. Moist air from the Pacific Ocean keeps dropping snow on the mountains, and valley glaciers spread out from the icefields.

Parks Canada describes the St. Elias Mountains as Canada's highest and most massive: the Kluane Ranges (averaging about 2,500 m) and the Icefield Ranges (peaks into the 5,000 m range), separated by the Duke Depression. Between them lies a legacy of the last Ice Age, one of the world's largest non-polar icefields, up to a kilometer deep in places; moist Pacific air keeps adding snow, and valley glaciers radiate from the icefields, some of them surging.

UNESCO describes the wider region as tectonically active, with continuous mountain building, and says over 200 glaciers on its ice-covered central plateau combine into some of the world's largest and longest glaciers.

Mount Logan's park is part of a huge protected wild area.

It joins parks in Canada and the United States.

Kluane National Park and Reserve is part of a UNESCO World Heritage site, first listed in 1979, that joins parks in Canada and the United States. UNESCO says it holds the largest icefield outside the polar regions and some of the world's longest glaciers.

Its land reaches from the sea, through forests, up to high alpine tundra, so many kinds of plants and animals live there.

The joint Kluane / Wrangell-St. Elias / Glacier Bay / Tatshenshini-Alsek property (inscribed 1979, extended 1992 and 1994; 9,839,121 ha) contains, in UNESCO's words, the largest non-polar icefield in the world and examples of some of the world's longest and most spectacular glaciers.

It runs from coastal and marine environments to some of North America's highest peaks, with life at many successional stages from 500 m below sea level to 5,000 m above, and is a showcase of moraines, hanging valleys and other glacial landforms.

Grizzly bears, Dall sheep and mountain goats live in the park.

Eagles fly over the valleys.

More than half of Kluane is always covered by snow and ice, but the rest has forests and tundra. Parks Canada says grizzly bears, Dall sheep and mountain goats roam the park, along with eagles.

Pacific and Arctic air meet over Kluane, which gives it some of the greatest variety of plants and wildlife in northern Canada.

Parks Canada notes that over half of Kluane is permanently under snow and ice, while the rest supports forests and tundra with stable populations of eagles, grizzlies and other species often at risk elsewhere; grizzly bears, Dall sheep and mountain goats roam its rugged land.

It attributes one of the greatest diversities of plants and wildlife in northern Canada to the climatic overlap of Pacific and Arctic air masses. UNESCO adds that the Tatshenshini and Alsek valleys give ice-free links from coast to interior for plant and animal migration.

Mount Logan is hard to see from the road. People look from special viewpoints far away.

High up, the air has less oxygen, and people can get headaches.

Parks Canada says most of Kluane's highest mountains cannot be seen from the highway, but some high peaks can be spotted in the distance from viewpoints near Kathleen Lake or the Donjek River.

Visitors who go high into the mountains can get altitude sickness. The US Centers for Disease Control and Prevention (CDC) says children are as likely to get it as adults, headache is its main sign, and going down at least 300 meters helps.

Parks Canada notes that most of the highest peaks are not visible from any point along the highway, though some can be seen in the distance from viewpoints near Kathleen Lake or the Donjek River.

For high-altitude travel, the CDC's Yellow Book says any unacclimatized traveler sleeping at 2,450 m or higher is at risk of altitude illness, children are as susceptible as adults, headache is the cardinal symptom of acute mountain sickness, and a descent of 300 m or more brings rapid improvement.