A drone shot of the layered Miocene basalts of the Grand Mesa Volcanic Field. The tan Green River Formation (Paleogene)—forming the hoodoos—is seen beneath talus accumulations at the base of the basalt flows, Lands End, Grand Mesa, Colorado, July 2017. Photo credit: Julian Chesnutt for the CGS.

Colorado Geological Survey

The Colorado Geological Survey (CGS) is a 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.

Our Mission

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.

More about the CGS

Stock groundwater well, Lost Creek Basin, Weld and Adams County, Colorado, August 2009. Photo credit: Colorado Geological Survey

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.

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Martin Marietta Aggregates in Jefferson County, Colorado, March 2013. Photo credit: Michael O'Keeffe for the CGS.

ON-007-01 Colorado Aggregate Resources Map

This interactive map includes the digital versions of our sand, gravel, and quarry aggregate publications for Colorado’s populous counties. The map consists of locations and resource ratings of these deposits to assist with land use planning and resource development.

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Quick Links

Aerial mapping tools, Paonia Quadrangle, Colorado, August, 2013. Photo credit: Dave Noe for the CGS.

Map Portal

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Publications

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MI-97 LiDAR-Based Map of the Cheraw Fault Scarp. Graphic credit: Colorado Geological Survey

GIS Data

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Looking northwest to Hells Kitchen from Ekkert, Colorado, towards Grand Mesa across the wide range of environments from

Colorado Geology

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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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ON-001 Colorado Earthquake and Fault Map

Earthquakes

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Who we are and what we do …

About the CGS

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!

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

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.

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A precarious rock above Manitou Springs started to move in 1995 after a period of wet weather. As an emergency measure, high-strength steel cables were wrapped around the rock and anchored to the surrounding ledge to arrest the movement. Photo credit Jon White for the CGS.

Case in point ::

Rockfall Case Study

Manitou Springs

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.

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Dramatic landslide headscarp threatens this structure on Constellation Drive in Skyway, Colorado Springs, Colorado, May 2017. Photo credit: Jon Lovekin, PG for the CGS.

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.

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Latest Reports & Featured Topics

Newest annual survey of the state ::

IS-84 Colorado Mineral and Energy Industry Activities 2020-2021

Exploring the seismic history of Colorado ::

MI-100 Summary Report on the McQueary Gulch Trench, Williams Fork Mountains Fault, Grand County, Colorado

An ongoing issue in Colorado ::

HAZ-2021-01 Post-wildfire Hazards: Mud Slides :: Debris Flows

A look into Elbert County water ::

OF-18-12 Geology and Groundwater Resources of Elbert County, Colorado

Strategic minerals on an ancient seashore ::

RS-48 Beach Placer Mineral Deposits along Localized Paleoshorelines of the Western Interior Seaway, Upper Cretaceous Fox Hills Sandstone, Eastern Denver Basin, Colorado

Recent Statemap quadrangle map ::

OF-21-04 Geologic Map of the Hardin Quadrangle, Weld County, Colorado

Newest Addition

Golden Rocks: The Geology and Mining History of Golden, Colorado

A detailed volume—written for the general public—that explores many fascinating features of the human and geological history of the town of Golden, the home to both the Colorado School of Mines and the Colorado Geological Survey. The authors, Donna Anderson and Paul Haseman generously made this comprehensive and well-researched work available for free to the public.

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Our most popular publications :: (Please note that physical publications for sale are being migrated to our Amazon storefront in the next weeks. All free digital downloads will continue to be available here.)