Flow Direction
A principal feature of the Chicago Portage water gap is that water can flow through it in either direction across the continental divide. It has flowed from east to west, west to east, or not at all. There have been two long-term reversals, and short-term reversals still happen today. Initially, water flowed from east to west starting about 10,000 years ago. About 3,000 years ago, this flow mostly stopped, and the Chicago Portage became a wind gap, except during floods when it flowed from west to east. In the year 1900, it was reversed to again flow continuously from east to west, except during floods when it can be reversed to flow from west to east.
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Famous quotes containing the words flow and/or direction:
“On the idle hill of summer,
Sleepy with the flow of streams,”
—A.E. (Alfred Edward)
“The mountainous region of the State of Maine stretches from near the White Mountains, northeasterly one hundred and sixty miles, to the head of the Aroostook River, and is about sixty miles wide. The wild or unsettled portion is far more extensive. So that some hours only of travel in this direction will carry the curious to the verge of a primitive forest, more interesting, perhaps, on all accounts, than they would reach by going a thousand miles westward.”
—Henry David Thoreau (1817–1862)