The Midwest was a world that owed its character to a combination of climate, topography, and soil. The glaciers to the north naturally influenced the territory to the south.

As the first Americans arrived, probably from the west or northwest, the northern zone was a thin band roughly comparable to the tundra of upper Canada. Farther south were forests similar to those of today’s Midwest. The people crossed a Mississippi River swollen with meltwater as it coursed southward from the glacial front.

But one cannot make strict analogies with modern environments, says University of Northern Iowa archeologist Michael Shott. “It was a complex patchwork,” he says. next >>

Today, one would have to travel many miles, from northern Canada southward, to experience a range of habitats from tundra to deciduous forest. The first people would have experienced much more change in a much shorter distance.

Shott says the scene was like an accordion, with the folds representing climate zones. “Today the accordion is stretched out,” he says. “Then it was squeezed tight, with the folds almost overlapping, not just pressed together. This made for a much richer mix of life.” next >>

Though the glaciers were in a gradual retreat, ice ruled the weather. “To a significant extent, climate was geographically determined,” Shott says.

Winters were cold, summers warm but short. Over time the climate slowly shifted toward modern conditions. Yet from about 10,900-10,100 years ago, North America experienced a period of abrupt and rather severe cold. After that, the warming trend resumed. << back