B-19 The Cretaceous Formations of the Northeastern Colorado Plains and the Foothills Formations of North-Central Colorado B-19 The Cretaceous Formations of the Northeastern Colorado Plains and the Foothills Formations of North-Central Colorado
B-12 Common Minerals and Rocks: Their Occurrence and Uses B-12 Common Minerals and Rocks: Their Occurrence and Uses (1917)
HM-04 1913 Topographic Map of Colorado (George) (detail) HM-04 1913 Topographic Map of Colorado (George)
B-06 Common Minerals and Rocks: Their Occurrence and Uses B-06 Common Minerals and Rocks: Their Occurrence and Uses (1913)
MI-19 Nell’s Topographical and Township Map of the State of Colorado (detail) MI-19 Nell’s Topographical and Township Map of the State of Colorado
HM-01-04 1877 Geologic Map of Colorado (Hayden) (detail) HM-01A Six 1877 Geologic Map Sheets and Two Cross Sections of Colorado (Hayden)