Roadside Geology of Yellowstone Country: Roadside Geology

while also delivering you to sites that have recorded the region's broadand deep geologic story, which includes exquisitely preserved, 50-million-year-old petrified trees buried in conglomerate; mountain-sized blocks of rock that slid more than 50 miles in a massive debris avalanche; the glacially carved craggy peaks and U-shaped valleys of the Beartooth Mountains and Absaroka Range; and the Grand

Canyon of the Yellowstone, the excavation of which is

still a mystery.