On a cold, rainy Saturday morning, about a dozen people hopped out of their trucks with helmets, headlights and other climbing gear at the side of a gravel road in Summersville, a small Ozark town located almost 200 miles from St. Louis.
They arrived on a mission to find five caves off the trail of the state-owned Gist Ranch Conservation Area, relying on decades-old records from the Missouri Speleological Survey.
Many records of Missouri’s caves don’t contain precise locations, since a lot of them were reported before sophisticated mapping technologies were developed. The state largely relies on recreational cavers to help track them down.
“We like being out, we like hiking. We like being in the woods, the adventure part of it,” said Jim Ruedin, a St. Louis-area resident who has explored caves for more than 20 years. “Even if we don’t find a cave, we still had fun."
According to state data, Missouri has more than 7,000 caves, the second greatest number of caves in the country (Tennessee has more than 10,000). The caves sometimes contain endangered species and artifacts from indigenous people. Explorations provide useful knowledge to the state, in case a developer wants to build in an area that may have caves.
The search for the first cave
Ruedin, a member of the Meramec Valley Grotto, led the recent survey in the Gist Ranch Conservation Area. It was the first time that members of the group, most from the St. Louis area, had looked for caves in this part of the Ozarks.
“Going to a new area, some place that we’re not familiar with is a part of what we get excited about,” Ruedin said. “We hope that we’ll find all five. You just never know until you get involved.”
As he held a map in his hand, he rallied other cavers in a circle around him.
“We’ll try to find this Rattlesnake Cave first,” Ruedin said, before asking caver Joe Light to ask if he wanted to take the map.
“I’m following you,” Light said. “You’re in charge.”
The cavers also use a topography app called Topo Maps, which shows physical features of an area on their phones. It’s useful because it works in areas where there’s weak cell signal, so it helps them look for caves and also find their way back, in case they get lost and separated from other cavers. Often, people will stray far from the trail to find caves.
The group struggled to find Rattlesnake Cave.
“It’s not screaming, 'Cave!'” Ruedin said. “We’re just not seeing things we typically see where we would be looking — you know, rock outcroppings. You’d see exposed rock and things like that. It’s not looking particularly karsty.”
That’s a reference to karst topography, a geologic term often used to describe areas where there are sinkholes and caves.
There’s very little information about Rattlesnake Cave, so the location reported to the state likely isn’t precise, Ruedin said. He was more confident about finding the other caves, since the records seemed more reliable. After an hour of looking, they cavers began their search elsewhere.
The story behind Missouri’s numerous caves
There are thousands of caves in Missouri, because limestone and dolomite underlie about two-thirds of the state. Limestone and dolomite are soluble, meaning that groundwater and rainwater move through the rocks and dissolve them to form caves.
St. Louis’ geology is largely defined by limestone. But dolomite dominates most of the Ozarks, which contain the largest concentration of caves in the state. Missouri has probably the most caves that are formed in dolomite, as opposed to limestone, said Jeffrey Crews, a geologist for the Missouri Geological Survey.
It seems counterintuitive, he added, since dolomite is less soluble than limestone.
“As the dolomite [rocks] get bigger and coarser, there’s more porous space between them that allows the water to move through them,” Crews said. “So what the process is losing by having less soluble minerals, it’s making up for it by having more porous space to allow more water to move through [the rocks].”
Limestone and dolomite deposits in the area likely occurred during rising sea levels that happened between 300 and 500 million years ago, Crews said. Before, the land that became Missouri had igneous rocks because of volcanoes in the area.
“It would be similar to the Caribbean today, [where] you see limestone reefs and shoals and a few mountains sticking up out of the water here and there,” Crews said. “That’s what Missouri would’ve looked like.”
Unlike caves in other states, Missouri’s are largely horizontal, due to “flat-lying” rocks that move water horizontally towards rivers and streams. The shape of rocks are largely influenced by mountains in the area. More mountainous states, like Tennessee and Kentucky, have more vertical caves.
“We have vertical caves, but they’re not hundreds of feet deep,” Crews said. “Our mountains aren’t tall enough.”
The value of exploring caves
Recreational cavers provide very useful information to state agencies, Crews said. The data informs them about potential environmental hazards, in case a utility company wants to build a landfill where a cave might be. They also shed light on the state’s water resources and help map spring systems.
The Meramec Valley Grotto finds about 100 caves a year.
“The citizens of Missouri have actually gotten a pretty good deal from these volunteers over the years,” Crews said.
Many cavers, for example, will help look for animals that are endangered or are relatively unknown to scientists. On a Saturday afternoon in December, Bob Weck, Illinois Speleological Survey president and biology professor at Southwestern Illinois College in Belleville, led a group of volunteers and high-school students into Cliff Cave in south St. Louis County to find cave snails.
While standing in a stream, he picked up a rock and asked an ecologist next to him to document it.
“Over in the notes, I would write ‘clean,’” Weck said. “That’s the phrase I use when there are no critters on it.”
Weck was interested in cave snails because few have been found.
Other caves contain Native American artifacts or fascinating items that help shed light on human history in the distant past. Craig Williams, a Meramec Valley Grotto member with an archaeology background, recalled a rare find about 10 years ago in a cave found at a farm near Springfield, Missouri.
“Cavers rappelled in, and they found that at one time, there was a walk-in entrance, and there’s prehistoric human footprints still in them, and torch marks,” Williams said.
Only 12 caves in the United States have prehistoric human footprints, he said.
The search for Gist Ranch caves becomes desperate
After about five hours in the woods looking for caves, the group began to give up.
“We don’t have that much more time to look for them,” Ruedin said, looking up at the sky. “We’re starting to lose light. We need to get back.”
One caver, however, was determined not to give up, so he waded across a fast-flowing stream to look at an area that the others agreed looked like it potentially had a cave. Adele Ayres, another Meramec Valley Grotto member, called out at him across the stream.
“Dang it, you gotta be kidding me,” Ayres said. “I think you gotta go back.”
“It looks very cavey,” she said to another caver. “Oh well.”
It can sometimes be hard to explain the appeal of caving to people outside of the group, Ruedin said.
“It’s like talking about your kids,” he said. “You know, everyone else’s kids are annoying, but your kids are the most fantastic amazing creatures on the planet. Caving is kind of like that. You know, if we told the story of how our morning went: We had a sketchy location, we went out in the woods, and it was rainy and wet and cold. We looked around for an hour and didn’t find anything like that. Why would you want to do something like that?”
But even though the group’s members did not find any caves on its recent excursion, Ruedin said they still enjoyed the experience.
“Cavers are definitely a community,” he said. “It’s kind of a subculture with its own set of values and norms. It’s a very tight-knit group, which makes it all the more fun when you are doing stuff and hanging out with people you like being around.”
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