Viewed from outer space, the Great Lakes resemble five fingers spanning the border between Canada and the United States. Due to the sheer size of these water bodies and the fact that they are landlocked, the Great Lakes create their own weather patterns. For example, cold air masses moving across the warm lake surfaces often result in increased snow or rainfall in the lake region. In the northern parts of these vast lakes, the climate is cold and the landscape is dominated by conifer trees. As the lakes extend south into the United States, the climate becomes warmer and the soils more fertile. These forests contain deciduous trees, which fill the region with brilliant colors in autumn before losing their leaves. Because the weather is warmer and the soils are more fertile, much of the southern Great Lakes region contains farms, cities, and towns. For example, Chicago is located in the southern basin of Lake Michigan.

Formed over a million years ago by massive glaciers, Lake Michigan, Lake Erie, Lake Huron, Lake Superior, Lake Ontario contain roughly 18% of the world’s fresh water. In addition to providing drinking water to human communities, the lakes also sustain diverse ecosystems. Fish species such as lake trout and salmon live in the rivers and lakes of the region, while birds and mammals make their homes in the surrounding wetlands and forests. The grey wolf, moose, black bear, peregrine falcon and bald eagle all live in the marshy wetlands and deep forests of this ecoregion.