Geologic Map of the Mount Trumbull 30' X 60' Quadrangle, Mohave and Coconino Counties, Northwestern Arizona by US Geological Survey's George Billingsley and Jessica Wellmeyer.
Online Resources:
1:100,000 scale map and report ~ https://pubs.usgs.gov/imap/i2766/
For an interactive map of Grand Canyon and environs, including Mount Trumbull
Photographer: George Billingsley
Photo Date: 2004