Minnesota's lakes may be its most famous features, but the glaciated countryside disguises a much longer history of volcanoes and plate collisions--not surprising when you learn that Minnesota was at the active edge of the fledgling North American continent for several billion years.

Have you ever wondered how the Mississippi River was formed? Or why shark teeth have been found in the Iron Range of the Upper Midwest? Towering mountain ranges, explosive volcanoes, expansive glaciers, and long-extinct forms of both land and sea life were an important part of Minnesota's ancient history. Today the evidence of this remarkable heritage is revealed in the state's rocky outcroppings, stony soils, and thousands of lakes.