When rocks talk, we listen!
The Colorado Geological Survey (CGS) is a non-regulatory state government agency situated within the Colorado School of Mines. We provide a wide range of science-driven services—this website being one—bringing the best of Colorado geoscience to the public.
To help reduce the impact of geologic hazards on the citizens of Colorado; to promote responsible economic development of mineral and energy resources; to provide geologic insight into water resources; and to proffer sound geologic advice and information to a variety of constituencies.
ON-010 Colorado Groundwater Atlas
Groundwater—as a critical natural resource for Colorado—is the focus of this informative and data-rich online publication from the CGS. Building on our previous award-winning Ground Water Atlas of Colorado, it features a wide range of easily accessible data from a variety of sources.ON-010
ON-007-01 Colorado Aggregate Resources Map
Many naturally occurring aggregates, such as sand, gravel, and crushed stone are produced around the state. They are used in a wide variety of ways including construction fill, concrete, road base along with rip-rap, snow and ice control, filtration systems, railroad ballast, hydraulic fracturing, and roofing granules.ON-007-01
Points of Geologic Interest
Given the spectacular geology that graces our state, we are happy to report that our new POGI map is now live! Check it out and let us know if you have any questions or additions!Learn More
Case in point ::
Landslide Case Study
2015 West Salt Creek
On May 25, 2014 the longest landslide in Colorado’s historical record occurred in west-central Colorado, taking the lives of three local men.
Case in point ::
Rockfall Case Study
Manitou Springs occupies a narrow valley where Fountain Creek emerges from the foothills northeast of Pikes Peak and west of Colorado Springs. The valley slopes are composed of interbedded resistant sandstone and conglomerates (i.e., gravelly sandstone), and weaker mudstones and shale.
Case in point ::
Land Use Case Study
Landslides in Colorado Springs
The city of Colorado Springs lies at the boundary between the Great Plains and the Front Range of the southern Rocky Mountains. Western sections of the city are underlain by weak claystones and shales that are prone to landslides.
Latest Reports & Featured Topics
Newest Miscellaneous Investigation (MI-) Series
MI-98 Catastrophic Glacial Outburst Floods on the Upper Arkansas River, Colorado
This publication from Mines Geology Professor Emeritus Keenan Lee is an in-depth exploration that illustrates one facet of the dramatic sweep of Colorado’s glacial past. With their high altitude, the central Rockies of Colorado saw numerous waves of intense glaciation, giving broad form to the mountains we see today. In particular, the Sawatch Range, with its Collegiate Peaks area to the west of the Upper Arkansas River valley was the site of glaciation several times in the last 700,000 years. Glacial terrains often feature dramatic ice- and land-forms. Lesser known are the occasional catastrophic events — also known as jökulhlaups — as are detailed in this report.
Check out the >RockTalk< blog for the latest news on the CGS and Colorado geoscience ::
- Recent STATEMAP quadranglesThe CGS actively participates in the STATEMAP portion of the US Geological Survey's National Cooperative Geologic Mapping Program (NCGMP), a … Read more
- Field SafetyIt's field mapping time, and much of our staff are out in several different areas of the state, doing field … Read more
- Colorado Scientific Society lecture onlineTITLE: Historic Avalanches in Hinsdale County, Colorado: Impacts to Lake City, old mining dams, and new evidence for the association … Read more
- New Colorado Groundwater Atlas releasedON-010 Colorado Groundwater Atlas
- OF-19-03 Geologic Map of the La Salle Quadrangle, Weld County, ColoradoAs we continue to expand geological mapping coverage of Colorado, we recently uploaded another of our STATEMAP 7.5-minute, 1:24,000 quadrangle … Read more
- Trenching the Cheraw Fault in Southeastern ColoradoOne of the missions of the CGS is to better understand the various geological risks that face the residents of … Read more
SP-43 A Guide to Swelling Soils for Colorado Homebuyers and Homeowners
SP-44 Geologic Excursions to the Rocky Mountain and Beyond, Field Trip Guidebook for the 1996 GSA Annual Meeting, Denver
SP-52 Messages in Stone: Colorado’s Colorful Geology (2nd Edition)
MI-94 Colorado Geologic Time Scale Bookmark