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 today.
More than 430 species of flowering plants as well as many species of mosses, lichens, fungi, algae, and others grace the slopes and valleys of Denali. Only plants adapted to long, bitterly cold winters can survive in this subarctic wilderness. Deep beds of intermittent permafrost ground frozen for thousands of years underlie portions of the park and preserve. Only the thinnest layer of topsoil thaws each summer to support life. After the continental glaciers retreated 10,000 to 14,000 years ago, hundreds of years were required to begin building new soils, and to begin the slow process of revegetation.