Wolf Creek Valley Overlook, Mineral County (September, CGS 2025 Geology Calendar). Photo credit: Nate Rogers (CGS).

Geology

2025 Colorado Geology Calendar

Back for the third year running, our popular annual calendar showcases a varied and beautiful photo tour around the state. We’re excited to share this next collection of photographs from current and former CGS staff members. Designed to keep you visually “in-the-know” on colorful Colorado geology, it reveals special locations…

The north face of Mount Lincoln (14
The north face of Mount Lincoln (14

Geology

2024 Colorado Geology Calendar

Following up on last year’s popular geological photo tour around the state, we’re proud to share this next collection from current and former staff members. Designed to keep you visually in-the-know on colorful Colorado geology, it reveals special locations throughout the year! You can order your calendar on our (new)…

Large 700-series Caterpillar mine hauling trucks at the Holcim Portland Cement plant in Florence
Large 700-series Caterpillar mine hauling trucks at the Holcim Portland Cement plant in Florence

Energy, General, Minerals, Publications

IS-85 Colorado Mineral and Energy Industry Activities 2021-2022

The current annual Colorado Mineral and Energy Industry Activities report for 2021-22 is now available. Following up on the 2020-21 report, this report is based on 2021 production data with additional reported news from 2022. It provides a comprehensive snapshot of Colorado’s mineral resource…

The Colorado River as it leaves the state
The Colorado River as it leaves the state

Water

Colorado Water Plan 2023

“Water is the lifeblood of our state, and we are taking strong actions to protect Colorado’s water for generations to come. As climate change places increased strain on Colorado’s precious water resources, we are taking a forward-thinking and innovative approach to ensure that all Colorado’s communities, farmers, and ranchers can…

Flooding and erosive flows following a 2004 rainstorm caused this bridge collapse in El Paso County. East Sand Creek had been
Flooding and erosive flows following a 2004 rainstorm caused this bridge collapse in El Paso County. East Sand Creek had been "channelized" upstream of this structure - possibly concentrating the flows and resulting in this damage. Photo credit: Colorado Geological Survey.|Bank erosion (cut bank caving) along the North Fork of the Gunnison River in Paonia

Hazards, Water

Case study: Fluvial Hazard Zone

“The Fluvial Hazard Zone (FHZ) is defined as the area a stream has occupied in recent history, may occupy, or may physically influence as it stores and transports water, sediment, and debris.” The CGS often collaborates with local, state, and federal agencies on projects concerning emergency preparedness and community…

Pyrite
Pyrite

Geology, Hazards, Publications, Water

Case Study: NARD

Are pristine mountain waters always clean and pure? Can streams unaffected by human activities and livestock influences be unfit for human consumption, or for aquatic life? The existence of natural acid rock drainage (NARD) suggests a “no” to the former, and a “yes” to the latter question. But…