Comal County abounds with natural wonders and unique wildlife, including amazing caverns and the largest bat colony in the world. These one-of-a-kind attractions will likely be negatively impacted by the 2.4-square mile Vulcan quarry.


Bracken Bat Cave

The proposed Vulcan Comal quarry site is just a few miles north of Bracken Bat Cave, home to 20 million Mexican Free-Tailed Bats—the largest colony of bats (of any species) in the world.1 Since 1992, various organizations have spent millions of dollars purchasing thousands of acres of nearby land for conservation and to prevent encroaching development around the cave. Now those efforts could be jeopardized by the 1500-acre quarry going in just up the road.

Bracken Bat Cave in Comal County, between Bulverde and Garden Ridge, Texas
Natural Bridge Caverns in Comal County near Garden Ridge, Texas

Natural Bridge Caverns & Wildlife Ranch

Natural Bridge Caverns are just three miles from the proposed quarry site. These are the largest known caverns in the state of Texas and feature many unique geological formations, including a 60-foot natural limestone slab bridge. The caverns drop 230 feet below the ground surface in some places and are home to a second large colony of bats.

Natural Bridge Wildlife Ranch, located just next door to the caverns, but stretching to the north (within two miles of the quarry site) is a 400-acre safari-style wildlife park. The drive-through ranch features over 500 animals (over 40 species), including zebra, gazelle, buffalo, and a very rare set of giraffe twins.


Endangered Species

Comal County is home to several species listed as endangered.2 Destruction of natural habitat, noise and light pollution, and disruption of water supply will negatively impact area biota and further jeopardize the following species:

  • Golden-Cheeked Warbler
  • Black-Capped Vireo
  • Whooping Crane
  • Comal Springs Dryopid Beetle
  • Comal Springs Riffle Beetle
  • Peck’s Cave Amphipod
  • Fountain Darter
Golden-Cheeked Warbler, an endangered species native to Comal County
Golden-Cheeked Warbler, an endangered species native to Comal County
Light pollution from machinery operating during night hours
Light pollution from machinery operating during night hours

Light Pollution

In the Hill Country, we like our stars big and bright. But those days may be coming to an end in central Comal County. The permit application for the Vulcan Comal quarry specifies continuous operations—24 hours a day, seven days a week, 365 days per year. During the night hours, large lights will illuminate the dark sky and create a continual nuisance for surrounding residents and wildlife.


Caves & Wildlife News

Quarries Pose a Risk to Local Caves, Water


Landowners discover new chamber in Double Decker Cave, in Comal County, Texas between proposed Vulcan quarry site and Natural Bridge Caverns.

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Bracken Cave Bat Experience


Wednesday, September 11, 2019: Experience the spiraling emergence of over 15 million Mexican free-tailed bats—the largest bat colony on the planet—as they begin their evening hunt.

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Texas Hill Country at Risk from Aggregate Mining


The unique natural resources of the Texas Hill Country are at increasing risk from aggressive expansion by aggregate mining companies proposing numerous rock quarries and cement plants throughout the region.

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Resources & Documents


Helpful resources, documents, and tools for protecting our families, preserving our beautiful Hill Country environment, and fighting the proposed Vulcan Materials quarry in Comal County.

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