Book excerpt: Since Mountain Press started the Roadside Geology series forty years ago, southern Californians have been waiting for an RG of their own. During those four decades�which were punctuated by jarring earthquakes and landslides�geologists continued to unravel the complexity of the Golden State, where some of the most dramatic and diverse geology in the world erupts, crashes, and collides. With dazzling color maps, diagrams, and photographs, Roadside Geology of Southern California takes advantage of this newfound knowledge, combining the latest science with accessible stories about the rocks and landscapes visible from winding two-lane byways as well as from the region�s vast network of highways. Join Arthur Sylvester, an award-winning UC Santa Barbara geologist, and Elizabeth O�Black Gans, a geologist-illustrator, as they motor through mountains and deserts to explore the iconic features of the SoCal landscape, from boulder piles in Joshua Tree National Park and brilliant white dunes in the Channel Islands to tar seeps along the rugged coast and youthful cinder cones in the Mojave Desert. Whether you want to find precious gemstones, ponder the mysteries of the Salton Sea, or straddle the boundary between the North American and Pacific Plates, be sure to bring this book along as your tour guide.