The Roadside Geology series originated in 1972 with iRoadside Geology of the Northern Rockiesi. Fourteen years later, the Big Sky portion of that book was updated to become iRoadside Geology of Montanai, a bright-yellow field guide that soon graced bookshelves across the state. Now, nearly 50 years after the first book, Mountain Press is releasing this completely revised full-color second edition that, like so many things in Montana, is big. But consider this no other place in the world has such amazingly diverse and well-exposed rocks with such dramatic stories. For example, Montana lies at the northern edge of the Yellowstone caldera, the world's largest and most violent volcano. A lot of what the wold knows about dinosaurs and their demise came from fossils discovered in Montana's badlands. What began with panning for gold in the 1860s led to 1-mile-deep mines in Butte that supplied 60 percent of the world's copper by 1898. The world's largest ice age floods left ripples up to 50 fe