Explore the landscapes, rocks, and resources of Texas and 1.7 billion years of Earth history in Texas Through Time by noted geoscientist Thomas E. Ewing. Visit the ancient rocks of the Llano and Van Horn areas, the legacy of now-eroded Himalaya-type ranges that initially rose more than 1 billion years ago. Marvel at the giant West Texas Basin, so prolific in oil and gas, and the enigmatic Marathon and Ouachita Mountains. Watch North America separate from the supercontinent Pangea and create the enclosed, salt-rich Gulf of Mexico in its wake.

This colorful geologic map published by AAPG—developed with assistance from the Bureau of Economic Geology—highlights state and regional surface rock outcrops, detailing their age, depositional environments, rock types, and formation names. The map is printed on a single sheet and folded to glove compartment size. It also features major highways, towns, landmarks, a stratigraphic column by state, mileage charts, and other interesting information about Texas geology.