Last updated: June 8, 2026
Place
Pleistocene Ice Ages
© 2013 Colorado Plateau Geosystems, Inc; used under license. http://deeptimemaps.com/
When you hear the words “Ice Age” what do you think? Ice, glaciers, and cold? Pleistocene Epoch Ice Ages were periods of both glacial and interglacial climates. These ice sheets were up to 0.6 to 1.2 miles (one to two kilometers) thick. Glaciers would expand and contract (grow and shrink), which affected North America’s environments.
With so much water trapped within the ice sheets, global sea levels were lower. The ice sheets also controlled river flow and could create colder, drier conditions south of the ice sheets. While most of Canada and the northern United States were covered in ice, southern portions of the United States remained ice-free.
With so much water trapped within the ice sheets, global sea levels were lower. The ice sheets also controlled river flow and could create colder, drier conditions south of the ice sheets. While most of Canada and the northern United States were covered in ice, southern portions of the United States remained ice-free.