Projects and Partnerships


Members of Colorado Western Slope Grotto have discovered the most paleontologicaly significant cave in Colorado, identified the largest gypsum cave in Colorado, the largest claystone cave in Colorado, and discovered a species of arachnid previously unknown in Northern latitudes. 

Additionally, our members oversee protection, restoration, and conservation efforts at one of the most heavily vandalized caves in the state, lead the development of managment recommendations for caves on federal lands, and continuously work to support the exploration, conservatoin, and study of the Western Slope underground.

Witch's Pantry Cave

Following the 2019 discovery of Witch's Pantry Cave by CWSG members. The Grotto initiated a project to explore and protect the cave. After 18 months, a complete cartographic survey, as well as geologic and biological inventories were submitted to the Bureau of Land Management (BLM).  Due to the geological, hydrological, and paleontological importance, the cave was officially designated a Significant Cave and is now protected under the Federal Cave Resources Protection Act (FCRPA).  Those protections may not be enough top protect the cave from a proposed limestone quarry expansion and CWSG members continue to advocate for the protection of this unique cave.  

The Claystone Caves

Soil piping erosion is a common occurrence on the Western Slope of Colorado due to clay-rich expansive soils.  Many of these erosional features are large enough to be classified as caves and are referred to as Claystone Caves.  The Colorado Western Slope Grotto works in cooperation with landowners, scientists, and other cavers to discover, document, and explore these unique geologic features on the Western Slope.

Great Horned Owl Cave

In 2020, Great Horned Owl Cave was discovered by CWSG members.  The following year, complete cartographic maps and scientific inventories were submitted to the BLM.  As the largest gypsum cave in the state of Colorado, the cave was officially designated a Significant Cave and is now federally protected under the FCRPA.

Pipeline Cave

Members of CWSG coordinated with private landowners, the BLM, and Colorado Parks and Wildlife (CPW) officers to conduct cartographic survey and scientific inventory of Pipeline Cave in Western Garfield County.  In 2021, the cave was granted Significant Cave status and is now federally protected under the FCRPA.

Cave of the Clouds Signature Record

With an extensive history dating to 1886, Cave of the Clouds has quite a story to tell.  Once a commercial cave where visitors were encouraged to sign their names on the cave walls.  After the tourist venture failed, the cave remained accessible to curious visitors.  By the mid-twentieth century, much of the cave was damaged by vandalism and graffitti.  The current owners created The Defiance Cave Presereve in 2018.  A gate was installed to protect the cave and restoration work began immediately.  In 2021, CWSG cavers began the arduous task of documenting the signatures.  So far, over 200 names have been identified!  Thousands more remain in the dark.

Rocky Mountain Cave Critters Coloring Book

You can't make a mistake. Anything that happens you can learn to use - and make something beautiful out of it. We don't have to be committed. We are just playing here. There are no mistakes. You can fix anything that happens. You have freedom here. The only guide is your heart. Don't fiddle with it all day. Trees grow in all kinds of ways. Van Dyke Brown is a very nice brown, it's almost like a chocolate brown. You can do anything here. So don't worry about it. 

Download a sample page here!

Recommendations for Cave and Karst Management -  White River National Forest Edition

The Colorado Western Slope Grotto works to proactively assist land managers in their work protecting, studying, and exploring caves.

This compendium of caver recommended conservation strategies, access protocols, and helpful worksheets to aid local forest service personnel tasked with the management of the unique and fragile karst landscapes found in the White River National Forest.

Contact the editor, Rob McFarland, to request a copy.


As a member grotto of The Colorado Cave Survey (CCS), Colorado Western Slope Grotto members provide an active voice to the elected body of cavers who serve as a liaison to maintain an open and cooperative relationship between the Colorado caving community and federal, state, and private land management agencies who own and/or manage many of Colorado’s caves. 

The longest cave in Colorado, and at a surveyed length of nearly 15 miles, one of the 60 longest caves in the United States, Groaning Cave represents a unique and fragile treasure. Perched atop a spectacular sub-alpine limestone canyon, Groaning’s network of crawls, fissures, domes and caverns has drawn cavers to marvel at its wonders and explore its depths for more than 50 years after discovery in 1968.  The cave is gated and access is managed by CCS volunteers from CWSG and many other Grottos across the state.  Download the Groaning Cave Hazards Disclosure form.

The privately-owned, 45-acre, Defiance Cave Preserve was established to protect multiple limestone caves and the cave life found within them.   Access to the preserve is managed by CWSG volunteers.

The Fairy Caves Project is a volunteer organization managing caver access to the caves of the privately-owned Glenwood Caverns at Glenwood Springs. The project also coordinates ongoing science, exploration, survey, and conservation projects.

The Colorado Western Slope Grotto is one of seven NSS Grottos in the state.  Members, friends, and colleagues from the Northern Colorado Grotto (NCG), the Southern Colorado Mountain Grotto (SoCoMoGro), the Timberline Grotto (TG), the Colorado Grotto (CG), Front Range Grotto (FRG), and the Colorado School of Mines Grotto (CSMG) routinely collaborate on caving projects.  Nothing gets done without help from friends!