Gary O'Brien

Job Title: Fluvial Geomorphologist
Primary Affiliation: Department of Watershed Sciences
Secondary Affiliation: Ecogeomorphology & Topographic Analysis Lab

Utah State University
Watershed Sciences Department
5210 Old Main Hill, NR 210
Logan UT 84322-5210

Office:  ECC 102
Office Phone: 435-757-5057

Personal Website:  Staff Profile


  • 1997, B.S. Geology, Northern Arizona University, Flagstaff
  • 2002, M.S. Geology, Northern Arizona University, Flagstaff


I am interested in the geomorphic and hydrologic processes that shape mountain, hillslope and riverine landscapes. Whole watersheds and their ecosystems adjust to cultural pressure and climatic change in styles that deserve careful study. My projects have focused on large desert rivers whose modern channel is modified by anthropogenic influence, and by climatic-driven fluctuations preserved in older records. I am motivated to understand drivers of environmental change on a variety of temporal and spatial scales.


Gary O'Brien is a fluvial Geomorphologist who, over the past 20 years, has worked on several research projects related to modern rivers, and ancient alluvial and paludal records. In addition to varied field applications (geomorphic mapping and stratigraphic profiling, GPS and total station surveying, river navigation and airborne photography), he has overseen logistical and administrative aspects of large research projects, taught university courses and mentored students in the field. In addition to research in riverine environments, Gary has been a professional river guide on many western rivers including the Grand Canyon, and currently enjoys mountaineering, cycling, and aviation.


  • Coordinating and conducting resaerch on the refinement, continued development and implementation of Rapid Geomorphic Assessments for ISEMP basins, including River Styles analyses, on-the-ground surveys and Aerial overflights. 
  • others coming soon...

Scholarly Contributions

 My publication profile in Google Scholar

Contribution to DataBasin

Peer Reviewed Publications

  • Pederson, JP., and O'Brien, G., 2014. Patterns in the Landscape and erosion of cultural sites along the Colorado River corridor in Grand Canyon, USA. Geoarchaeology 29, 431-447.
  • O'Brien, G., Kaufman, D.S., Sharp, W.D., Atudorie, V., Parnell, R.A., Crossey, L.J., 2006. Oxygen isotope composition of annually banded modern and mid-Holocene travertine and evidence of paleomonsoon floods, Grand Canyon, Arizona, USA. Quaternary Research 65, 366-379.
  • Kaufman, D.S., O'Brien, G.R., Mead, J.I., Bright, J., Umhoefer, P., 2002. Late Quaternary spring-fed deposits of the Grand Canyon and their implication for deep lava-dammed lakes. Quaternary Research 58, 329-340.      

Conference Papers, Presentations & Posters


  • O'Brien, G., and Wheaton, J., 2015. River Styles report for the Middle Fork John Day Watershed, Oregon.  Ecogeomophology and Topography Analysis Lab, Utah State University, Prepared for Eco logical Research, and Bonneville Power Administration, Logan, Utah, 215 pp. DOI: 10.13140/2.1.3251.2329
  • O'Brien, G., Wheaton, J., and Bouwes, N., 2015. Synthesis and Recommendations from Middle Fork John Day River Styles - Leveraging the River Styles Framework in Tributary Habitat Management for the Columbia River Basin. Fluvial Habitats Center, Utah State University, Prepared for Eco Logical Research and Bonneville Power Administration, Logan Utah, 20 pp. DOI: 10.13140/2.1.3937.3129.
  • Pederson, J., O'Brien, G., Neff, T., and Spurr, K., 2011. Grand Canyon Geoarchaeology Projgect: Report on Data Recovery at Nine Cultural Sites in Grand Canyon and Lower Glen Canyon 2008-2010. Final report submitted to U.S. Bureau of Reclamation, Upper Colorado Region.
  • Cannon, K.P., and O'Brien, G., 2011. The 2010 Field investigations of the Salmon River Heritage Project, Nez Pearce National Forest, Idaho County, Idaho. USUAS Technical Report 2011-005, US Forest Service Report No. R2012011700009.
  • O'Brien, G., and Pederson, J.L., 2009. Gully Erosion Processes and Parameters at Six Cultural Sites along the Colorado River in Grand Canyon National Park, Arizona. Final report submitted to USGS, Grand Canyon Monitoring and Research Center, Flagstaff, 123 p.
  • Pederson, J., O'Brien, G., and Damp, J., 2009. Grand Canyon Geoarchaeological Project - 2009 field season annual report, treatment at five sites in Grand Canyon. Final report submitted to the Bureau of Reclamation, Salt Lake City, UT, 209 p.
  • O'Brien, G., and Pederson, J.L., 2008. Geomorphic Attributes of 232 Cultural Sites along the Colorado River in Grand Canyon National Park, Arizona. Final report submitted to USGS, Grand Canyon Monitoring and Research Center, Flagstaff, 194 p.
  • Damp, J.D., Pederson, J.L., O'Brien, G., 2007. Geoarchaeological Investigations and and an Archaeological Treatment Plan for 151 Sites in the Grand Canyon, Arizona. Final report submitted to the Bureau of Reclamation, Salt Lake City, UT, 501 p.
  • Thompson, K.S., Potochnik, A.R., Ryel, R., O'Brien, G., Neal, L.A., 2000. Development of a geomorphic model to predict erosion of pre-dam Colorado River terraces containing archaeological resources. SWCA Environmental Consultants, Inc., report 99-257, Bureau of Reclamation cooperative agreement No. 1425-98-FC-40-22610, 193 p.
  • O'Brien, G., Burke, K., and Hamilton, L., 2000. Effects of continuous high flows and daily fluctuating flows on Grand Canyon Beaches, 1997-1999: a study of repeat photography by Grand Canyon River Guides, Inc. (Adopt-a-Beach Program). Administrative report submitted to Grand Canyon Monitoring and Research Center (USGS-GCMRC).
  • O'Brien, G., and Roberts, C., 1999. Evaluation of a river beach carrying capacity information utilized by the Grand Canyon River Trip Simulator (GCRTS): analysis and recommendations for future study: Final report submitted to the National Park Service, Grand Canyon Science Center (CA8210-99-002) May 1, 1999, 17 p