Going underground

Lynne Padilla (left), Anna Padilla, and Emily Pettit check out the entrance to the Robber Baron cave on San Antonio's Near Northeast Side. The three women are part of a large group of volunteers working to restore the cave and its surroundings. (Photos by Mark Greenberg)

The Robber Baron Cave Restoration Project is transforming an ugly vacant lot into a history-filled neighborhood park

At the corner of Nacogdoches and Camellia lies a portal to another dimension that begins at a torn fence and continues to the rim of a two-story drop that cuts a wide spiral into a sinkhole. At the bottom, two passages burrow into the Austin Chalk rock, as if a giant could stick his feet into a pair of slippers.

Geologically, ecologically, and historically rich, Robber Baron Cave is the longest cave in Bexar County, winding beneath the city streets in an elaborate maze of 100 intersections. "It's like dropping a pile of spaghetti on your plate," says hydrogeologist George Veni, who is leading the cave's restoration.

Several groups, including the Texas Cave Management Association, Bexar Grotto, and the Texas Parks Foundation, are restoring Robber Baron Cave, one of the city's hidden - literally - treasures.

When it's finished, says Veni, "it will be a nice little gem that the neighbors can be proud of."

Since the 1950s, the cave has been obscured in the scrub of an ugly vacant lot. But in the '20s and '30s, when Arthur Harp owned the property, the cave teemed with as many as 300,000 explorers, and legend has it, bootleggers and other ne'er-do-wells. Harp often conducted guided tours of the cave, and allowed the brave to forge it on their own. After awhile, Harp was afraid amateur spelunkers would get hurt, and blasted shut some of the passageways.

"We've found new sections here and there," says Veni, who has explored the cave for 30 years. "There's more cave than is indicated right now."

Stanford Busby eventually bought the property, and when he died, bequeathed the cave to the Texas Cave Management Association. In 1980, Veni installed a steel gate at the cave entrance, although people still broke in and damaged the cave interior. The steel gate was replaced with a five-ton concrete bunker buttressed by railroad ties. Over time, the ties began to fail, rendering the bunker unsafe.

While the bunker successfully kept trespassers at bay, it also presented environmental hazards. Ecologists were concerned that creosote could leach into the cave from the railroad ties, and that cave crickets, which forage outside and then return to the cave, couldn't come and go. The bunker blocked the flow of nutrients, such as leaves, organic material, and water from entering the cave, threatening the fragile ecosystem that sustains endangered species, including six species found nowhere else in the world, that live inside.

Michael Parker directs Robert Lara, Joe Mitchell, and Charles Bishop as they place a large rock on the rim of the Robber Baron cave in Alamo Heights. A large group of volunteers were on hand to clean up and landscape the land surrounding one of San Antonio's legendary urban caves.
The TCMA received a $6,500 grant to redo the gate and grounds to make it more biologically friendly, and for the past two years, nearly 100 volunteers have worked at cleaning up the area. Construction debris created an artificial floor on the sinkhole, and it had to be excavated with a Bobcat. Workers trenched the sinkhole and restored the cave entrance with a new gate that allows air, water, nutrients and cave creatures to move freely, while keeping people out, except during guided tours.

The beige trench walls are made of Austin Chalk, a limestone rock composed of fossilized coccoliths, or golden-brown algae. The cave passages are fossil-rich limestone, which fractured into corridors after water seeped through clay and hit limestone below. Over time, the fractures enlarged and connected with one another until the cave developed a network of long passages that crisscross.

In his research, Veni interviewed former spelunkers who reported that Robber Baron connects with another cave about 1/4-mile away. It is sealed and is located on private property. Other cave explorers, including Ted Zetner who traveled Robber Baron in 1918, reportedly told Veni that it contained a stream and a lake.

"He told me, 'We used to go into the cave a lot; we decided we were really going to push this cave,'" Veni recalls, who sat with Zetner at the corner of Broadway and Nacogdoches, near the former site of a farm, when Zetner told the story several years ago. "They took a compass and went southwest and kept going until they got to a lake. They splashed around in the water and when they got out, they went over land to the farmer and told him they had found the source of his water. And he said, 'You're the ones that muddied my water.' It was the only time muddy water had come out of his well."

While the byproducts of urban development - pavement and runoff - seem at odds with cave preservation, cave restorers and U.S. Fish & Wildlife are working to protect the area while honoring the private property rights of neighborhood residents.

"There's a concern that endangered species could be affected by pesticides, herbicides, and runoff," says Veni. U.S. Fish & Wildlife sent letters to neighborhood residents encouraging them to minimize their use of fertilizers and pesticides. "But the neighbors aren't required to do anything," Veni adds. "We're not going to take anyone's land."

Additional work includes stabilizing and polishing the trench, installing xeriscaping and native plants as natural erosion controls, and building a footbridge over the sinkhole. Concrete steps will also be poured for visitors to safely descend into the sinkhole. Eventually, the site will be surrounded with a natural stone fence, backed by boulders to keep drunken drivers from breaching the fence and plunging 30 feet below.

The TCMA will offer guided tours of the cave, 84 percent of which is walkable; the remainder requires explorers to crawl through passageways.

Yet primarily, Veni says, "It will be a neighborhood park. We're trying to convert it into a nice little gem. There will be gates to make the subtle but clear statement that you're entering a special little place."

By Lisa Sorg

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