Millions of years ago, the North American continent was dragged over the world's largest continental hotspot, a huge column of hot and molten rock rising from the Earth's interior that traced a 50-mile wide, 500-mile-long path northeastward across Idaho. Generating cataclysmic volcanic eruptions and large earthquakes, the hotspot helped lift the Yellowstone Plateau to more than 7,000 feet and pushed the northern Rockies to new heights, forming unusually large glaciers to carve the landscape. It also created the jewel of the U.S. national park system: Yellowstone. Meanwhile, forces stretching apart the western U.S. created the mountainous glory of Grand Teton National Park. These two parks, with their majestic mountains, dazzling geysers, and picturesque hot springs, are windows into the Earth's interior, revealing the violent power of the dynamic processes within. Smith and Siegel offer expert guidance through this awe-inspiring terrain, bringing to life the grandeur of these geologic phenomena as they reveal the forces that have shaped—and continue to shape—the greater Yellowstone-Teton region. Over seventy illustrations—including fifty-two in full color—illuminate the breathtaking beauty of the landscape, while two final chapters provide driving tours of the parks to help visitors enjoy and understand the regions wonders. Fascinating and informative, this book affords us a striking new perspective on Earth's creative forces.