Keller, S. M., and M. L. Morgan, eds. Unfolding the Geology of the West. Geological Society of America Field Guide 44. Geological Society of America, 2016.
Keller, Stephen M., Kassandra O. Lindsey, and Matthew L. Morgan. “OF-17-03 Geologic Map of the Berthoud Quadrangle, Larimer, Weld, and Boulder Counties, Colorado.” Geologic, 1:24,000. Open File Reports. Golden, CO: Colorado Geological Survey, 2017. https://coloradogeologicalsurvey.org/publications/geologic-map-berthoud-quadrangle-boulder-larimer-weld-colorado.
———. “OF-19-02 Geologic Map of the Gowanda Quadrangle, Weld County, Colorado.” Geologic, 1:24,000. Open File Report. Golden, CO: Colorado Geological Survey, December 2021. https://coloradogeologicalsurvey.org/publications/geologic-map-gowanda-quadrangle-weld-colorado.
Keller, Stephen M., and Matthew L. Morgan. “New Paleocurrent Measurements in the Late Eocene Castle Rock Conglomerate, East-Central, Colorado.” In GSA Abstracts with Programs, 45, no. 7:241. Denver, CO: Geological Society of America, 2013. https://gsa.confex.com/gsa/2013AM/webprogram/Paper225142.html.
———. “OF-16-01 New Paleocurrent Measurements, Clast Population Data, and Age Dates in the Late Eocene Castle Rock Conglomerate, East-Central Colorado: Remapping the Fluvial System, and Implications for History of the Colorado Piedmont and Front Range.” Geologic. Open File Report. Golden, CO: Colorado Geological Survey, 2016. https://coloradogeologicalsurvey.org/publications/paleocurrent-geology-eocene-castle-rock-conglomerate-colorado.
———. “OF-18-01 Geologic Map of the Frederick Quadrangle, Weld and Broomfield Counties, Colorado.” Geologic, 1:24,000. Open File Report. Golden, CO: Colorado Geological Survey, 2018. https://coloradogeologicalsurvey.org/publications/geologic-map-frederick-quadrangle-weld-broomfield-colorado.
———. “OF-20-05 Geologic Map of the Greeley Quadrangle, Weld County, Colorado.” Geologic, 1:24,000. Open File Report. Golden, CO: Colorado Geological Survey, February 2021. https://coloradogeologicalsurvey.org/publications/geologic-map-greeley-quadrangle-weld-colorado.
———, eds. “Overview of the Eocene Castle Rock Conglomerate, East-Central Colorado: Remapping the Fluvial System, and Implications for the History of the Colorado Piedmont and Front Range.” In Unfolding the Geology of the West, 125–41. Geological Society of America, 2016. https://doi.org/10.1130/2016.0044(05).
Kirkham, Robert M., Karen J. Houck, Neil R. Lindsay, and Stephen M. Keller. “OF-07-06 Geologic Map of the Garo Quadrangle, Park County, Colorado.” Geologic, 1:24,000. Open File Report. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 2007. https://coloradogeologicalsurvey.org/publications/geologic-map-garo-quadrangle-park-colorado.
Morgan, M. L., P. E. Barkmann, and Stephen M. Keller. “OF-12-04 Elbert Quadrangle Geologic Map, Elbert and El Paso Counties, Colorado.” Geologic, 1:24,000. Open File Report. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 2012. https://coloradogeologicalsurvey.org/publications/geologic-map-elbert-quadrangle-elbert-el-paso-colorado.
Morgan, Matthew L., Stephen M. Keller, W. R. Premo, D. P. Miggins, and R. J. Moscati. “Clast Lithology, Population, Provenance and U-Pb Geochronology – What Can the Late Eocene Castle Rock Conglomerate Tell Us About the History of the Colorado Piedmont and Front Range?” In GSA Abstracts with Programs, 45, no. 7:478. Denver, CO: Geological Society of America, 2013. https://gsa.confex.com/gsa/2013AM/finalprogram/abstract_225084.htm.
Morgan, Matthew L., David C. Noe, and Stephen M. Keller. “OF-07-01 Geologic Map of the Olathe Quadrangle, Delta and Montrose Counties, Colorado.” Geologic, 1:24,000. Open File Reports. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 2007. https://coloradogeologicalsurvey.org/publications/geologic-map-olathe-quadrangle-montrose-colorado.
Noe, David C., Matthew L. Morgan, Stephen M. Keller, and Hanson, Paul R. “OF-07-02 Geologic Map of the Montrose East Quadrangle, Montrose County, Colorado.” Geologic, 1:24,000. Open File Reports. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 2007. https://coloradogeologicalsurvey.org/publications/geologic-map-montrose-east-quadrangle-colorado.
O’Keeffe, Michael K., Marieke Dechesne, Matthew L. Morgan, Katharina Pfaff, and Stephen M. Keller. “Critical Minerals in Beach Placer Deposits of the Fox Hills Sandstone, Elbert County, Colorado.” In Geological Society of America Abstracts with Programs. Vol. 51, No. 5, Vol. 51. Tucson, AZ, 2019. https://doi.org/10.1130/abs/2019AM-337497.
O’Keeffe, Michael K., Matthew L. Morgan, Stephen M. Keller, Kenneth L. Horkley, and John W. Keller. “RS-47 Reconnaissance of Potential Sand Sources in Colorado for Hydraulic Fracturing.” Resource. Resource Series. Golden, CO: Colorado Geological Survey, 2018. https://coloradogeologicalsurvey.org/publications/potential-sand-sources-hydraulic-fracturing.
Smith, J. J., A. L. Layzell, W. E. Lukens, M. L. Morgan, S. M. Keller, R. A. Martin, and D. L. Fox. “Getting to the Bottom of the High Plains Aquifer: New Insights into the Depositional History, Stratigraphy, and Paleoecology of the Cenozoic High Plains.” In Unfolding the Geology of the West, 93–124. Geological Society of America Field Guide 44. Boulder, CO: Geological Society of America, 2016. doi:10.1130/2016.0044(04).