Two climbers are known to have been killed exploring the Devil's Sinkhole in western Texas, and perhaps 2,000 others have got in and out of it safely in the century since the white man discovered it. Attempts at exploitation—extracting guano, lowering sightseers into the gloom—have failed. The sinkhole, with its small subterranean mountain, its immense bat colony and its crystalline lakes, remains pretty much an underground wilderness. It seems to resist human meddling, partly by being unpleasant. It fascinates many people, but it smells of bats. It's mysterious, offering the possibility of discovering fantastic caverns no man has ever seen, but looking for them is dangerous.
The Devil's Sinkhole is roughly the shape of a funnel turned upside down, with the little end at the surface of the earth. The narrow part of the funnel is technically the sinkhole, and it leads down to the big room called the cavern. The sinkhole is in a rocky pasture, on a ranch 10 miles east of Rocksprings, Texas, in a region of the state known as the Edwards Plateau.
There's a hole in the ground 60 feet across and 140 feet deep. At the bottom, where direct sunlight never reaches, is a jumble of rocks. But it isn't really the bottom; it's the point where the funnel begins to grow wider. The rocks are the summit of the mountain—formed by a geological process that has been dissolving limestone from the upper walls over thousands of years—that fills much of the big room below. When people descend by rope or cable they come to rest on this rock pile and then must scramble 160 feet down its slopes to reach the base.
The room in which they find themselves is 240 feet wide, 360 feet long and irregular in shape. It's wide at the bottom and narrow at the top. Enough daylight comes down through the sink to allow one to get around without a flashlight. But getting around isn't easy. The rocks are loose—they range from automobile size to mere chips—and many are covered with a foot of guano. In summer, millions of bats cling overhead on parts of the ceiling not covered by stalactites. In winter, they migrate to Mexico and South America.
At various points around the perimeter of the room are pools of water. They are called lakes, though some of them are no bigger than a living room and only three or four feet deep. The pools are so motionless that all suspended matter settles to the bottom, and the water is as clear as air. People step into the ponds not realizing that there's water there.
The biggest lake is about 20 feet by 70 feet and has a small room to itself, the Lake Room. You reach it—and here you'll need a flashlight—through a tunnel or passageway in the rocks, and when you come to the water's edge you are 310 feet underground, as deep as you can go in the sinkhole without putting on scuba gear. By flashlight you can examine stalactites on the ceiling of the Lake Room and the vast boulders in the depths of the water. Some people go swimming, but only briefly because the water is cold.
Scuba diving is dangerous in the lakes because of crevices and unknown passageways and is best left to the experienced, the well-equipped and the very careful. When they plunge beneath the surface of a lake, the divers hope to find an underwater passage, follow it and emerge in a new room or perhaps on the bank of an underground river. So far this hasn't happened. But it could, because beneath the Edwards Plateau lies one of the great cave regions of the world. There are fissures and caverns and springs by the thousand; the suspicion is that because of their inaccessibility, most of the geological phenomena are undiscovered. Many Texas cities have speleological clubs and many universities have biologists who explore and map the reachable parts of this underworld to study the animals that live in it.
The plateau is a limestone slab about the size of West Virginia. On the surface it's almost entirely ranch country—thin-soiled and dry, with scrubby trees, good grass and prickly pear. The water is underground. When a rancher drills a well and finds that for decades he can pump out all the water he and his livestock need, whether it rains on the surface or not, he assumes he has tapped an underground river. These rivers come to the surface in the form of springs along the southern edge of the plateau, where they supply cities and industries and military bases with water. The biggest of these rivers, the Comal, produces 200 million gallons a day.
A man named Clarence Whitworth bought the Devil's Sinkhole Ranch in 1927, when he was 27. In 1934 he married Katherine Nicholson, a young woman from the cotton country of central Texas. They raised cattle, sheep and goats in the rocky, silent pastures until Clarence's death in 1981. Katherine still owns the ranch. It's not a particularly large one for that part of the world—six sections. A section is a piece of land a mile square. Much of West Texas is still owned, fenced and ranched in these huge squares, there having been no occasion as yet to subdivide them.
In the days of the open range, a herd of stampeding Longhorns might easily have been swallowed up by the Devil's Sinkhole. But it was far from the major cattle trails, and this never happened. No fence is needed now to keep the pasture's livestock from falling in. "You can't get a horse within a hundred yards," Clarence once told me. "Cattle, either. Goats, they'll graze a little closer." Katherine believes that all the animals in the pasture, cougars and skunks and jackrabbits as well as livestock, sense danger in the smell of guano and keep away.