User:Bettymnz4/Minnesota River Valley subprovince

The Minnesota River Valley is a trench originating on the western border of Minnesota, trends southeasterly to Mankato, Minnesota, U.S., then bends sharply to the northwest where it joins the Mississippi River at St. Paul, Minnesota. It is up to 60 m deep and almost 5 km wide in places. About 12,000 years ago a glacial lake overtopped a natural earthen dam near Brown Valley, Minnesota; the waters from the lake scoured the land. This scouring exposed a 400 km trench which exposed 3500 million years of geologic history.