Roadside Geology of the Yellowstone Country (Roadside Geology Series) (Roadside Geology Series)

The geologic story of the Yellowstone Country begins with rocks 2.7 billion years old that are mashed remnants of even older rocks, and continues with processes that shape the land surface today. Striking evidence lies along the park roads and highways leading to the north, south, east, and west entrances to Yellowstone Park.