Devil's Sinkhole

Useful Information

Location:	Devils Sinkhole Visitor Center, 101 N. Sweeten St., Rocksprings, TX 78880. 10 km northeast of Rocksprings in Edwards County. State Highway 55 to Rocksprings, 10 km north on US Highway 377. (30.057550, -100.109152)
Open:	Evening tours: MAY to OCT Wed-Sun before sunset. Morning tours: MAY to OCT on select days before dawn. by reservation only. [2022]
Fee:	Evening tours: Adults USD 14, Children (4-11) USD 6, Children (0-3) free, Seniors (65+) USD 11. Morning tours: Adults USD 20, Children (0-11) USD 10. [2022]
Classification:	Doline
Light:	n/a
Dimension:	A=747 m.
Guided tours:
Photography:	allowed, no flash
Accessibility:	yes
Bibliography:
Address:	Devils Sinkhole Visitor Center, 101 N. Sweeten St., Rocksprings, TX 78880, Tel: +1-830-683-2287. E-mail: Devils Sinkhole Society, Tel: +1-830-683-BATS(2287) Devils Sinkhole State Natural Area, PO Box 678, Rocksprings TX 78880, Tel: +1-830-683-3762.
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then. Please check rates and details directly with the companies in question if you need more recent info.

History

1867	discovered by the 28-year-old ranch foreman Ammon Billings.
1876	named by the wives of Ammon Billings and other men who had discovered the entrance after an encounter with Indians.
1971	declared a National Natural Landmark by President Nixon.
1985	acquired by the Texas Parks & Wildlife Department.
1992	opened to limited access.
1996	picnic sites, a chemical toilet, some trail development, and a viewing platform.

Description

Devil's Sinkhole is a collapsed cavern, a so-called daylight shaft or pothole which is 12 by 18 m wide and 42 m deep. However, collapse doline or sinkhole is also a valid name for such a pothole. It is the entrance to the main chamber of the cave, which is about 120 m deep. The cave is not developed, and it is not possible to enter it. Its fame is actually a result of estimated 3 million Mexican Free-Tail Bats (Tadarida brasiliensis mexicana) which live in the cave, making it one of Texas’ largest colonies of Mexican free-tailed bats.

Mexican free-tailed bats roost in the cavern from late spring to early fall. During the colder months of the year they migrate to Mexico. They leave the cave every evening for feeding and return in the morning. It was estimated that they consume up to 30 tons of insects each night.

There is a viewing platform for visits organized by the Rocksprings Visitor Center. They take place while the bats roost at the approximate time they leave the cave every evening. There is a good chance to see a cloud of bats leaving the cave like an erupting volcano, but the bats do not always conform to the tour schedule.