Atlas of Sand Gravel and Quarry Aggregate by quadrangle. Set of all 213 plates, reduced and compiled. 213 plates (1:24,000). Digital PDF download. See SP-05A for additional related info. SP-05BD
From the preface:
In 1973 House Bill 1529 charged the Colorado Geological Survey to “contract for a study of the commercial mineral deposits in the populous counties of the state in order to identify and locate such deposits. Such study shall be of sand, gravel, and quarry aggregate, and shall be completed on or before July 1, 1974, and shall include a map or maps of the state showing such commercial mineral deposits, copies of which may be generally circulated. Any commercial mineral deposits discovered subsequent to July 13 1974, may be, upon discovery, included in such study.”
The study area covered approximately 16,000 square miles, including Adams, Arapahoe, Boulder, Denver, Douglas, El Paso, Jefferson, Larimer, Pueblo, and Weld Counties. Results of this study were distributed as:
1. This SP-5A containing explanatory text and three l:250,000-scale regional maps.
2. Detailed 1:24,000-scale quadrangle maps to the appropriate counties and cities within the project area. Copies could be obtained from the CGS or acquired from the appropriate county planning offices.
3. The SP-5B atlas containing a compilation of reduced-scale preliminary maps, which is intended to provide a convenient substitute for the more expensive and bulky detailed maps.