Preliminary Digital Geologic Map of the Gillette 30’ x 60’ Quadrangle, Campbell, Crook, and Weston Counties, Northeastern Wyoming (1999)

Boyd, C.S., and Ver Ploeg, A.J., 1998, Preliminary digital geologic map of the Gillette 30’ x 60’ quadrangle, Campbell, Crook, and Weston counties, northeastern Wyoming: Wyoming State Geological Survey Hazards Section Digital Map 99-1, scale 1:100,000.