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A Journey to a New Land

Mammoths and tundra
Post secondary Level Resources

Environment in the Ice-free Corridor

By at least 13,000 to 12,000 years BP, the Cordilleran and Laurentide ice sheets began to recede and an ice-free region emerged along the eastern flanks of the Rocky Mountains. However, the environment in this periglacial landscape would have been very inhospitable for early human or animal travelers. Aside from being cold and windy, much of the corridor would have been blocked by large ice-dammed glacial lakes that formed as the ice sheets melted. When the ice dams broke, catastrophic outburst flooding inundated wide areas of the landscape. This early environment would not have been productive enough to support human populations – few plants or animals could have survived in this hostile landscape.

Though it is unlikely that any human group could have remained in these areas for much time, early travelers were likely skilled at traversing harsh environments. Modern mountaineers are familiar with these areas and can attest to the need for specialized understanding and experience to cross the types of environments. There is no reason to doubt that early explorers had similar expertise at their disposal, as well as the experience necessary to cross this harsh landscape, if it was required.

Over the course of time, however, glacial lakes drained, temperatures rose, and new plant life began to take hold. Grasses, herbs and shrubs were the first vegetation to appear, and this steppe tundra environment attracted and supported herds of grazing animals such as bison and caribou. By about 11,000 years BP, archaeological evidence confirms that groups of hunters had moved into the ice-free corridor region, and were harvesting the plant and animal resources that were flourishing there.

Archaeology in the Ice-Free Corridor
Geology in the Ice-Free Corridor
Environment of the Ice-Free Corridor
A South to North Migration?