wide as the state is big, sweeping from volcanic mesas and thrusting mountains in the west to red canyons of the Panhandle, along tropical sand barriers of the Gulf Coast, and across central limestone plateaus onto hard granitic terrain in the center of the state. Texas is bless with rocks of all ages, as well as an incredible array of natural geologic resources. Darwin Spearing will tell you about the rocks as you come to them--describing what they are, when they formed, what they mean, and how they fit into the big picture of the geology of Texas.