About This Work: Sources

Stratigraphic Chart

This living digital chart has been built directly from a chart of Colorado Stratigraphy assembled by Richard H. Pearl published by the Rocky Mountain Association of Geologists in Special Publication 2 in 1977. The chart has been reproduced in various ways for field guides and handouts. We have recast it against the International Commission on Stratigraphy’s  Chronostratigraphic Chart v. 2015/01 and slightly modified the organization and layout. Thanks to Larry Scott for drafting the stratigraphic chart. It is designed, like Colorado, to evolve with time.

Paleogeographic Maps

These maps are the work of Ron Blakey, published in:
Blakey, R. and Ranney, W., 2008, Ancient Landscapes of the Colorado Plateau; Grand Canyon Association, 156  pp., together with maps from a CD obtained from Ron featuring additional maps of the Western Interior.  For additional details please see Ron’s publications and www2.nau.edu/rcb7

Paleogeologic Maps

Bob compiled these from the literature. They form a part of a research project at the Denver Museum of Nature & Science to examine Colorado’s evolving river systems.

Ancient Paintings

These come from the book:  Ancient Denvers: Scenes from the past 300 million years of the Colorado Front Range by Kirk Johnson and Bob Raynolds, published by the Denver Museum of Nature & Science, with artwork by Jan Vriesen, Donna Braginetz, and Gary Staab. Ten images, painted by Jan Vriesen, from the Colorado Convention Center have been added courtesy of the artist, the Denver Museum of Nature & Science, and the City of Denver.

Fossil Photos

We are adding photos of representative Colorado fossils, using images from the Denver Museum of Nature & Science and the University of Colorado.

Strata Photos

We are collecting a series of beautiful photos of rocks in Colorado. We have used photos form Jeremy McCreary’s web site at www.cliffshade.com and other resources as indicated. We also include Herb Saperstone's annotated 360° photographs of special geologic places: www.kulla.com.

Resources (Coal, Oil, Gas)

This page illustrates resources extracted in Colorado. The data have been derived from the Colorado Oil and Gas Conservation Commission, the Colorado Geological Survey and the Energy Information Administration by Kathy Robinson. The size of the circles are proportional to the resource volume extracted. For more detail, see the metadata download on the individual resource pages.

Coal Production Sources:

  • 1864-2002: Colorado Geologic Survey, Historic Coal Mines of Colorado, 2002, CD.
  • 2003-2017: EIA, Detailed data from the EIA-7A and the U.S. MineSafety and Health Administration by Year, http://www.eia.gov/coal/data.cfm#production
  • Coal production is reported in short tons, we converted to million short tons (MMSt)

Oil and Gas Production Sources:

Log Cross Sections

These come from the 1977 Rocky Mountain Association of Geologists Special Publication 2 edited by Dennis Irwin, Chair of the RMAG Research Committee. Committee members include: Lou Bortz, Lionel Brenneman, John Chronic, William Clark, Harold Dunn, Thomas Fisher, Lyle Hale, Dennis Irwin, Roger Matuszczak, Daniel McClure, Cornelius (K) Molenaar, David Moore, Duane Mordock, Richard Pearl, Soli Shapurji, Robert Wellborn, William Whiteley, and John Wilson.

Structural Cross Sections

These come from a compilation by William Nesse, published by the Rocky Mountain Association of Geologists.

Measured Sections

These sections come from a volume published by the Rocky Mountain Association of Geologists, A Symposium Edited by Edwin D. McKee, 1957.

Stratigraphic Panels (Under Construction)

Bob is compiling panels of stratigraphic information along the Colorado Front Range tied directly to measured sections as indicated. The stratigraphic panel along the Uinta Piceance and Eagle basins comes from the U.S. Geological Survey Map I-2184-A by S. Jackson and R. Johnson 1990.

Paleogeography Videos

These videos were made by concatenating Ron Blakey’s paleogeographic maps.

Interactive Geology Project Videos

These videos are provided courtesy of Paul Weimer and his team at University of Colorado, Boulder.  For more videos and additional information, see igp.colorado.edu

Road Logs (Under Construction)

These were compiled by Bob Raynolds over a period of many years. They are currently under construction. Any input is welcome and appreciated.


April Johnson led the design and architecture of this website. The site was begun in 2014. The construction of this site is an ongoing process in which material is continually added and revised. Many of the graphics were created by Teresa Hill. April Johnson also created and compiled several of the graphics. Gabe Johnson assisted with the programming of the site. This effort became a prototype for two other websites and was a model for their creation. These additional sites focusing on northern Kenya and northern Pakistan can be found at: Turkanastratigraphy.org and Siwalikstratigraphy.org.

Many people have been involved in assembling this material. Jessica Don from the Colorado School of Mines helped build the chart; James Hagadorn of the Denver Museum of Nature & Science provided encouragement and perspective. His efforts at establishing a regional research project on the drainage history of Colorado spurred this effort. Working with Chris Holm-Denoma at the US Geological Survey we are using detrital zircon dating and provenance studies to establish regional stratigraphic patterns and to integrate the evolution of Colorado’s strata with work done at Colorado College by Christine Siddoway and elsewhere in the Southwest led by George Gehrels and William Dickinson.

Many people have provided advice; a list that still grows. Your input is also welcome!

Stratigraphic guidance has been generously provided by:

Lon Abbott
Donna Anderson
Peter Barkmann
Paul Belanger
Karen Berry
Don Boyd
Bruce Bryant
Steve Cather
Jim Cole
Rex Cole
Marshall Deacon
Marieke Dechesne
Jessica Don
Sven Egenhoff
Eric Erslev
Emmett Evanoff
James Evans
Frank Ethridge
Robert Fillmore
Gary Gianniny
Robbie Gries
David Gonzales
Bill Hood

Chris Holm-Denoma
Karen Houk
Mark Izod
Sam Johnson
Ron Johnson
Craig Jones
James Kirkland
Mark Kirschbaum
Karl Kellogg
Mark Kirschbaum
Louise Kitley
Eric Leonard
Michael Lewin
David Lindsey
Tyler Lyson
Ian Miller
Vince Matthews
Ian Miller
Scott Minor
Paul Myrow
Bill Nesse
Piret Plink-Bjorklund
Barney Poole

Libby Preuher
Don Rasmussen
Larry Rasmussen
Samantha Richards
Peter Robinson
Cal Ruleman
Charlie Sandberg
Matt Sares
Joe Sertich
Ralph Shroba
Bruce Shumacher
Christine Siddoway
Beth Simmons
Steve Sonnenberg
Ned Sterne
Lou Taylor
Paul Umhoefer
John Warme
John Webb
Bob Weimer
Paul Weimer
Jeremy Workman

Presentations were made to the Colorado Scientific Society (January 2016), Rocky Mountain SEPM, USGS Seminar Series, and at the GSA Regional Meeting, Casper (Summer 2015). Whereas every effort has been made to portray the stratigraphy comprehensively, there are various patterns and nuances that remain under discussion. We hope these charts and maps will continue to evolve with your and other colleagues' input. Together we hope to learn more about the evolution of Colorado’s landscapes and strata. Hence the chart will be updated; please note the date at the bottom left corner of the chart.

Bob Raynolds
James Hagadorn


Paul Weimer's Interactive Geology Project Visualizations at University of Colorado Boulder: igp.colorado.edu

Brian Penn's website describing the igneous history of the Spanish Peaks region: spanishpeakscolorado.com

Shellie Luallin's 3D photographic fossil renderings: sketchfab.com/Paleogirl

Herb Saperstone's annotated 360° photographs of special geologic places: kuula.co

Ken Steele, Mark Fisher, and Deb Steele have assembled a remarkable volume of geological and cultural information across the state of Wyoming: geowyo.com

Jeremy McCreary's geologic photos of Colorado attractions: cliffshade.com

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