The oldest rocks in America are about 3.5 Billion years old and the youngest are less than an hour old. What happened during America's long geologic history to form the landscape we see today? Find out about the processes that have physically shaped our country including the movement of the earth's crust, volcanoes, earthquakes, ice sheets and changing sea level. Why are the Great Lakes so great? How did lessons learned at Mt. St. Helens save lives thousands of miles away? Why does Yosemite have such amazing scenery? Why is Yellowstone one of the dangerous places on Earth? Where is a new ocean forming? Where are the oldest rocks in America? All this and more! No prerequisite needed.