Alyeska is set in the vast wilderness of Alaska - a land of brooding mountains, great rivers, forests and desolate treeless tundra. The film explores how the plants and animals have evolved to cope with the remarkably harsh and unrelenting Alaskan climate. Conditions, where for eight months of each year the land is locked in the icy grip of winter - temperatures can plunge to -60°, deep snow carpets the frozen ground, and lakes and rivers lie sealed under a mantle of thick ice.
Suddenly the of the spring thaw heralds a dramatic transformation. An explosion of plant life races to exploit the short growing season and spectacular numbers of migrant birds and animals move in to breed and feed during this brief time of plenty. But soon the animals sense the summer is drawing quickly to a close and that they must prepare for the onslaught of winter.

Birds become restless and start to leave in huge numbers heading for warmer climate, caribou abandon the bleak tundra plains and trek south to the shelter of their forested wintering grounds, and grizzly bears fatten themselves prior to their long winter sleep. Once again the Arctic Wilderness becomes rigorously cold and inhospitable as the long dark winter sets in.