Ice Ages

North America has been covered in ice many times. We may, in fact, now be in a brief interlude of a much longer ice age. The Museum's Ice Age display explains the effects of the most recent glacial advances.

An ice age is any part of several periods or epochs of time when glaciers, especially in the form of great ice sheets , covered more of the Earth's surface than they do today.

The North American plains cooled in the latter half of the Cenozoic. Spreading south from the Hudson's Bay area and eastwards from the Rocky Mountains, great ice sheets scraped across the northern half of our continent four times during the last two million years.

Falling sea levels during parts of the ice age periodically exposed a narrow land bridge between Asia and North America. Across the bridge moved many living things. North American natives, included camels, horses and cheetahs migrated to Asia. Mastodon, mammoth, bison and muskox crossed the other way. Behind them, pursuing an important food supply, came our own species, Homo sapiens.

This document was prepared by Wayne Hortensius, Calgary, Alberta, Canada for the Royal Tyrrell Museum Cooperating Society. All information © 1995 Royal Tyrrell Museum. All Rights Reserved.
Updated: April 8, 1995

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