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.
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

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
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.
ON-007-01Quick Links
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!
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.
Learn More
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.
Learn More
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.
Learn MoreLatest Reports & Featured Topics
Newest annual survey of the state ::
IS-83 Colorado Mineral and Energy Industry Activities 2019-2020
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.
Check out some of our RockTalk blog postings ::
HAZ-2021-01 Post-wildfire Hazards
Noting that we were getting hundreds of search hits on a previous version of an info-brochure that we originally published…
It’s field mapping time, and much of our staff are out in several different areas of the state, doing field…
Case Study: The Trinidad, Colorado Earthquakes
[ED: Originally published in 2011 by Vincent Matthews, former State Geologist at the CGS.] Around midnight on August 22,…
OF-16-03 Colorado Rocky Mountain Front Profiles
(Ed: We’re reprising this blog post because we find that this poster is getting more and more popular with folks—for…
Trenching the Cheraw Fault in Southeastern Colorado
One of the missions of the CGS is to better understand the various geological risks that face the residents of…
Case Study: mine subsidence, CSM
For decades, the west side of the Colorado School of Mines (CSM) main campus had subsidence issues related to…
Small but significant areas of Colorado are underlain by bedrock that is composed of evaporative…
Early History The Colorado School of Mines first acquired and installed a single three-component seismograph in the…
Our most popular publications ::
-
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-66 Colorado Rockfall Simulation Program, Version 4.0
-
SP-57 Tourist Guide to Colorado Geology
-
IS-33 Gold Panning and Placering In Colorado: How and Where
-
MI-16 1979 Geologic Map of Colorado (Tweto)
-
MI-94 Colorado Geologic Time Scale Bookmark
-
MS-42 Colorado Springs Landslide Susceptibility Map, El Paso County, Colorado
-
RS-28 Gold Occurrences of Colorado
-
MS-51 Interpretive Geothermal Gradient Map of Colorado
-
OF-16-03 Colorado Rocky Mountain Front Profiles
Contact Us:
Colorado Geological Survey
Street and Mailing Address:
1801 Moly Road
Golden, Colorado 80401
telephone :: [+1] 303-384-2655
email :: cgs_pubs@mines.edu