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What is the Devil’s Sinkhole?

Discovered in 1876 by a 28-year-old ranch foreman named Ammon Billings, the Devil’s Sinkhole has fascinated people all over the world for many years

Created a National Natural Landmark in 1971 by President Nixon, the Sinkhole is both the largest one-chamber cave in Texas and the fifth-deepest cave in Texas.

The cave is a very special habitat for many interesting plants and animals, including a crustacean found nowhere else on earth!

The tiny, blind Devil’s Sinkhole Amphipod that swims in the three lakes inside the big cave is, however, much less well known than the seasonally massive bat colony that arises from the cave every evening during bat season.

The Devil’s Sinkhole’s Mexican freetail Bat Colony is currently estimated at 4 to 6 million bats at the height of bat season. As the May-October bat season progresses, bat numbers typically go through three phases: May-June, the “kilo-bat” phase; July-early August, the “mega-bat” phase; and late August-October 31, the “giga-bat” phase.

Did you know …?

The Devil’s Sinkhole is …

  • Largest one-chamber cave in Texas.
  • Fifth-deepest cave in Texas.
  • Home to the fourth-biggest bat colony in Texas
  • A National Natural Landmark
  • Home to four endangered species
  • An 1836-acre State Natural Area
  • One of only three Texas Parks facilities with restricted access

The Devil’s Sinkhole State Natural Area is a Texas Parks and Wildlife facility. Tours are operated by the nonprofit Texas Parks friends group called the Devil’s Sinkhole Society 830-683-2287. The official park staff is based at Kickapoo Cavern State Park 830-563-2342.