Earthquake tremors both mild and moderate are frequent occurrences in the park and preserve. The building of these massive mountains began out of a flat lowland. The material that Earth's inner turmoil thrust up has subsequently been eroded, sculpted, and weighed down by huge masses of ice. Numerous glaciers still radiate from the high peaks of the Alaska Range, where the frigid temperatures prevent their melting. Some of the glaciers are visible from the park road.
Geologists say that Mount McKinley still rises.
Wildlife of Taiga and Tundra Spring, summer, and fall provide a compressed respite from the subarctic's long season of deep cold. For most animals it is a busy respite during which they must garner most of their annual food supplies. Ewes and rams live apart in summer, while the lambs are getting their start. In early summer sheep are at lower elevations, but they will follow the snowmelt higher and higher as summer progresses. Caribou, like the Dall sheep, travel in groups.