http://pubs.usgs.gov/imap/i2766/mtrreadme.txt

Version 1.2, March, 2014
  - Minor edits were made to the geodatabase to correct geology
    and facilitate edgematch with adjacent USGS maps.
  - The database was upgraded from ArcGIS 9.3 to ArcGIS 10.2.
  - Changes made to the geodatabase are not reflected in the
    pamphlet or on map sheet PDFs.

Version 1.1, January 1, 2007

  - Internal database structure and feature attributes 
    were modified to match other geologic map databases 
    being created for the Grand Canyon region.
  - One map unit was added because it was mislabeled in 
    the original. Qt (travertine) on the north edge is 
    really Qtr (talus). So we added the Qtr unit to the 
    database to reflect that correction.


U.S. Geological Survey Scientific Investigations Map I-2766
Geologic Map of the Mount Trumbull 30' x 60' Quadrangle, Mohave
and Coconino Counties, Northwestern Arizona

Description of digital dataset files posted on this website:

mtrreadme.txt - this file

mtrmeta.txt - FGDC compliant metadata. Each Geodatabase Feature
Class also has its own metadata.

mtr_db.zip - Zipped package of files necessary to create an
ArcMap Personal Geodatabase project.
   -- readme_mtrdb.txt
   -- MountTrumbull_v1.2.mdb - Personal Geodatabase
   -- mounttrumbull.style - ArcMap style for symbolizing data
   -- f36113a1.tif - 1:100,000-scale DRG base
   
mtr_shape.zip - zipped package of feature classes conveerted to
shapefiles to facilitate use of the data in ArcMap and other
applications.
   -- readme_mtrshape.txt
   -- mtr_shapefiles_v1.2 - shapefiles folder
   -- mounttrumbull.style - ArcMap style for symbolizing data
   -- f36113a1.tif - 1:100,000-scale DRG base