The headscarp of the West Salt Creek landslide. Photo Credit: David C. Noe for the CGS


Colorado has diverse geologic structures, rocks, soil types, topography, and climatic conditions that combine to create a range of dynamic natural processes. Where people choose to build communities and live determines whether these ongoing processes become threats in the form of geologic hazards including avalanches, floods, landslides, debris flows, earthquakes, and swelling soils. Over the years these hazards have cost citizens across the state billions of dollars in damages.

The CGS conducts scientific studies of the state’s geologic hazards, monitoring areas susceptible to geologic hazards and disasters and producing maps and guides as to where hazards may be encountered and how people might reduce their personal exposure. Importantly, the CGS studies both the natural occurrence of these hazards as well as how human activity sometimes unknowingly trigger them. The award-winning CGS publication “Collapsible Soils in Colorado” is an important resource that helps the public understand and mitigate a common geologic hazard that is often exacerbated by human activities. As directed by state statute, our staff of geo-engineering experts review geologic reports for certain new development in unincorporated areas of the state, as well as all new school or critical facilities construction, to determine whether they are at risk from geologic hazards. We also provide post-disaster and emergency-response assessments to affected areas and communities, helping to identify areas at risk of further damage.

Geologic Hazards

ON-001 Colorado Earthquake and Fault Map


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Historic coal mine subsidence incident in Boulder County, Colorado, March 2003. Photo credit: T.C. Wait for the CGS.

Ground Subsidence

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Swelling Soils

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Abandoned mine structures in the Pike-San Isabel National Forest, Colorado. Photo credit: Colorado Geological Survey

Abandoned Mine Lands

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West Salt Creek rock avalanche viewed from the air, May 2014. Photo credit: Jon White for the CGS.


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Constellation Drive landslide, Colorado Springs, Colorado, August 2015. Photo credit: T.C.Wait for the CGS

Land Use Review

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