Geologic Cross Section Along Interstate 40

“The rock layers exposed along Interstate 40 across northern Arizona reveal millions of years of time.” – Text, bottom.

This precisely illustrated diagram presents the subterranean geologic strata along the route of Interstate 40 in Arizona. One side of the sheet shows the highway from Kingman to Flagstaff, while the verso continues to the New Mexico state line. The primary image identifies the major rock structures as they sit beneath the surface, with various geographic features (including the Grand Canyon, Petrified Forest National Park, Meteor Crater, Humphrey’s Peak, etc.) labeled above. Cross-sections immediately below provide date ranges for specific formations in select areas.

The image was designed by George H. Billingsley and William J. Breed, with artwork by Dick Beasley. Published in Flagstaff by the Petrified Forest Museum Association in 1980. Lithographed by the Pagosa Press of Chandler, Arizona.