SP-05B Atlas of Sand SP-05B Atlas of Sand, Gravel, and Quarry Aggregate Resources, Colorado Front Range Counties
B-20 Preliminary Notes on the Revision of the Geological Map of Eastern Colorado B-20 Preliminary Notes on the Revision of the Geological Map of Eastern Colorado
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