This work-in-progress represents a spectacular set of data generated by George Billingsley and others at the USGS. The geologic data shown here was taken from the following USGS publications:

• Geologic map of the Mount Trumbull 30 x 60 quadrangle
• Geologic map of the Grand Canyon 30' x 60' quadrangle
• Geologic map of the Valle 30' x 60' quadrangle
• Geologic Map of the Cameron 30' x 60' Quadrangle
• Geologic Map of the Peach Springs 30' x 60' Quadrangle
• Geologic map of the Tuba City 30' x 60' quadrangle

"I just hiked my ass off in the canyon gathering the field data." -George Billingsley, 2013

Website by Ryan Clark, 2013. Problems? Suggestions? Please let me know!