Devil’s Sinkhole houses bats and serves as a portal to an underground world.
When it comes to big holes in the ground, there’s no other hole like Devil’s Sinkhole.
A 50-foot-wide shaft serves as a portal into a deep, dark subterranean world — Texas’ largest single-chambered and fifth-deepest cave. The shaft leads to an underground cavern, which reaches 350 feet deep.
About 1 million years ago, acidic groundwater started carving a huge cavity into the underground limestone. When the cavity drained, the cavern’s ceiling collapsed, forming the sinkhole.
Today, the sinkhole is a summer home to millions of bats on the western edge of the Edwards Plateau near Rocksprings.
The state acquired the cave in 1985 and opened it to the public in 1992. It is registered as a National Natural Landmark. Access to 1,860-acre Devil’s Sinkhole State Natural Area is limited to guided tours; reservations are required.
From May to October, visitors can witness the spectacular sight of hundreds of thousands of bats swirling out of the cave at dusk. On a summer night, the sinkhole colony may consume up to 30 tons of beetles and moths. In addition to seeing the bats, visitors can peer into the depths of the cavern from a viewing platform.
Devil’s Sinkhole is home to several archeological sites that date back to prehistoric times. The area has been inhabited by humans for thousands of years, and artifacts such as projectile points and pottery have been discovered in and around the sinkhole. Devil’s Sinkhole holds an important place in indigenous belief systems, with many tribes considering it a sacred site. Native American tribes believed the sinkhole to be a portal between the spirit world and physical world, and some saw the sinkhole as a gateway to the underworld.
Anglo travelers discovered Devil’s Sinkhole in 1867. The name is attributed to Ammon Billings, who called it “the outlet to hell, the devil’s own sinkhole.” H.S. Barber is the first person known to venture into the depths of the sinkhole. He carved his name and “1889” into a rock at the bottom. How Barber got down there remains a mystery.
Workers installed a rickety ladder into the cavern in the 1920s to collect guano for use in fertilizer and gunpowder. During World War II, scientists collected bats from Devil’s Sinkhole for a top-secret mission called Project X-Ray, in which bats were to deliver fire-bombs to enemy cities in Japan. After a series of tests, the bat bombs were deemed somewhat effective, though they were never deployed in battle.
These days, the bats themselves must avoid being dive-bombed: On bat emergence nights, great horned owls and red-tailed hawks are known to swoop into the swirling column of bats in search of a quick and easy meal.
