SAN JOSÉ STATE UNIVERSITY
ECONOMICS DEPARTMENT
Thayer Watkins

Mid North America
Before and Afterthe Last Ice Age

The topography of North America was consider different from what it is now before the last ice age. The Great Lake formed from the melting glaciers. There was temporarily a lake larger than all the Great Lakes combined, called Lake Agassiz after Louis Agassiz, the discoverer of the phenomena of the ice ages. Lake Agassiz developed due to river flows blocked by the glaciers. When lake Agassiz found outlets to Hudson Bay and Lake Superior, as well as the Mississippi River, it mostly drained away, although there are the remnants called Lake Winnipeg and Lake Manitoba left. The upper Missouri River drained into Lake Agassiz rather than following the present channel.

The present Ohio River follows the southern edge of the glaciers. This channel was maintained even after the glaciers retreated. Prior to the ice age the river drainage was along a channel through what is now the states of Ohio, Indiana and Illinois. The Teays (taze) River in West Virginia follows the old channel until it intersects with the Ohio River. The ancient river is referred to as the Teays River. Its channel can be seen in the map below.

Before the last ice age the Allegheny and Monongahela Rivers instead of flowing together to form the Ohio River separately drained into Lake Eire.

The ancient Teays River disappeared on the surface, in part because of the moraines left by the retreating glaciers, but underground the there is still a flow along the ancient river bed. A coal company in Indiana once sunk a shaft looking for coal deposits. The site the company chose just happened to be over the ancient Teays River bed. Instead of coal the company found water, lots of water. The company shortly changed its name to a water company and started selling water to the surrounding municipalities.

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