Caverns of Sonora

The Caverns of Sonora hid behind a pit for half a century. The entrance was found around 1900 on Stanley Mayfield's ranch — the story goes a dog chased a raccoon into a twenty-inch hole — and generations of ranch hands and local kids explored the first 500 feet as far as the Devil's Pit, a fifty-foot drop that ended the cave for everyone. The decorated half of the cave sat on the other side of that drop, unseen.

Labor Day weekend 1955, a Dallas crew — Danny Sheffield, Jack Allen, Claude Head, Jack Prince — crossed a narrow ledge high above the pit where three Abilene cavers had spotted the passage two weeks earlier. What they found beyond it stayed secret in the caving community for years: a seven-and-a-half-mile cave dense with formations unlike anything in Texas — helictites shaped like soda straws and fish fins, coral trees, and the famous Butterfly, a pair of symmetrical fishtail helictites the cave's signature.

Jack Burch, an Oklahoma caver, saw the damage careless visitors were already doing and argued the only way to save the cave was to commercialize it — his airlock doors and trails preserved the 71-degree, 98-percent-humidity interior, and the Caverns opened in 1960 as a model of development-as-conservation. The file keeps the trade: the Butterfly was vandalized by a visitor in 2006 — the risk Burch accepted — against a cave that preservationists still rank among the most beautiful on earth.

Caverns of Sonora is the archive's hidden-half file — the Texas ranch cave whose decorated chambers waited fifty years behind a fifty-foot pit, and the caver who opened it to the public to keep the public from destroying it.