A Force for Nature

By Bonnie Chasteen | July 1, 2019
From Missouri Conservationist: July 2019

“Do you think it could have been a short-faced bear?”

In the light of our headlamps, we saw two sets of deep claw marks on the cave wall, maybe 2 yards apart.

Tom Aley considered his answer.

Eleven thousand years ago, the short-faced bear was the most common ursid in North America. It was also enormous, possibly the largest meat-eating land mammal that ever lived. A big one weighed nearly a ton and stood 6 feet high at the shoulder, able to look a tall man like Tom right in the eye. It’s not hard to imagine the big bears holing up here in Tumbling Creek Cave, formerly known as Bear Cave.

“It could have been a short-faced bear,” Tom says. “But I think it was a black bear.” Tom’s wife, Cathy, a tall person herself, shot him a look. For nearly 50 years, they’ve led field trips through this cave, which they own, and they’ve no doubt had a version of this conversation more times than either of them can remember.

“Oh,” she says, “I didn’t know you’d decided that.” They laugh.

The Aleys are both scientists. He’s a longtime cave enthusiast and a forester-turned hydrologist. She’s a limnologist, someone who studies the ecological systems of freshwater lakes and other inland waterways. As fellow scientists and business partners, they are collaborative and mutually supportive. And, like most long-married couples, they keep each other honest.

Each is a force of nature, and together they’re a force for nature, especially the part most people don’t often see — a mostly hidden landform known as karst.

Characterized by underground drainage systems with caves and sinkholes, karst develops in limestone and other soluble bedrock. It occurs on every continent on Earth except Antarctica, and it receives, stores, and releases vital groundwater. It also serves as essential habitat for some of Earth’s rarest and most endangered lifeforms, like the federally endangered Tumbling Creek cavesnail. Studying karst systems, figuring out how to trace them, educating people about them, and protecting them has been the Aleys’ vocation and avocation since Cathy joined Tom at his Ozark Underground Lab (OUL) in 1974.

A lot has been written, in the Conservationist and elsewhere, about Tumbling Creek Cave, the most biologically diverse cave west of the Mississippi, and efforts to save its endemic cavesnail from extinction. But this story is about the Aleys, their influence on karst conservation efforts worldwide, and what they’re doing to ensure their legacy endures long after they’ve hung up their headlamps for the last time.

A Global Village

Famous for his sense of humor, Tom likes to quip that Cathy does all the work, and he gets all the credit. But he’s serious about recognizing the many people who have helped them develop their campus and groundwater-tracing business and conduct field trips over the years.

Family, professors, teachers, scientists, and caving enthusiasts — even the real estate agent who sold Tom the cave in 1966— became part of the Aleys’ extended clan. Cavers produced a detailed map of the cave, and many  taxonomists identified the cave’s species, describing and naming three new ones. Cavers and MDC staff volunteered to build the massive bat gate at the cave’s natural entrance.

“It has taken a village, and we greatly appreciate all the villagers who have joined with us,” Tom said. “Great conservation efforts require a lot of people and a lot of effort.”

To run their underground lab, they employ nine people. Using Tumbling Creek Cave to test their groundwater-tracing methods, the Aleys developed strategies for dealing with large volumes of water and “doing it with very small amounts of dye,” Tom said. “This led to a lot of consulting and tracing work, which we do all over the world.”

MDC Stream Program Coordinator Paul Blanchard contracted services from OUL, and he recognizes the Aleys’ role in advancing dye-tracing techniques.

“One of the most fundamental aspects of hydrology is understanding how the system is connected both above and below the ground,” he said. “Hydrologists add dye as a tracer to determine if two points are, in fact, connected. Tom worked hard at improving this method and instituted many procedures that have become standard practice now.

“The U.S. Forest Service, National Park Service, and MDC have all contracted with the Aleys for conducting dye traces related to critically important springs, caves, streams, and their dependent biota,” Blanchard said.

The Aleys see their business and their outreach efforts as mutually supportive. “All the company’s income over the years has gone into supporting the cave’s conservation needs,” Tom said.

A New View of Endangered Species

One of the many villagers the Aleys attracted to their operation is Dr. David Ashley. He was teaching biology at Missouri Western State University in the early 1990s when he took his first cave biology class down to Protem for an OUL field trip.

“The trip was such an incredible success,” Ashley said. “Everything Tom talked about related to our cave biology class, but it was all new to me. It was such a major learning experience.”

Ashley became a regular visitor, bringing student groups to the cave on an annual basis. When the Aleys noticed a sharp dip in their cavesnail numbers in the mid-1990s, the U.S. Fish and Wildlife Service (USFWS) asked Ashley to collect data to determine what was happening. His monitoring confirmed their observations.

“In the mid-1970s, we knew we had a population of about 15,000,” Tom said. “By 2000, the population had dropped to 150.” In 2002, USFWS listed the Tumbling Creek cavesnail as endangered. Although the Aleys were distressed about the cavesnail’s downturn, they viewed the listing as a blessing. With it came funding and support to help find and fix the problems that were driving the snail’s decline: erosion from overgrazing, sewage from a local school, and the invading native ringed crayfish from Bull Shoals Lake.

Tom said they’ve done very well by managing the cavesnail and its listing as an asset, not a liability. “The community has done well,” he said. With a new sewer system, “the school is still there serving the neighborhood.”

Studying the Surface

The Aleys lead field trippers into the cave to reveal what happens when land is mismanaged.

“We’ve taken about 40,000 people on our daylong trips to help them better understand interactions between the surface and subsurface in cave country,” Tom said, “Most have been college students.”

Field trips begin on land known as the recharge area that lies over the cave. According to OUL’s flow records, about 50 percent of all the runoff water from this 9-square-mile area sinks into the ground and ultimately flows through Tumbling Creek Cave.

When Tom first bought the cave, he didn’t own much of the recharge area’s 5,800 acres. But after the cavesnail’s decline pointed to problems like sedimentation from overgrazed land, he and Cathy started buying up recharge-area acres.

To date, the Aleys have bought and restored more than 3,500 acres of land. Restoration activities included stabilizing stream banks, repairing erosion gullies, and planting 75,000 trees.

When I visited the Aleys’ prairie and pastureland last September, Cathy told of degraded pastures and erosion gullies with cattle bones. But with their careful restoration, the late summer prairie was abloom with tall grasses and wildflowers, and it buzzed with bees, butterflies, and countless other species of pollinators.

Cathy and Tom credit renowned malacologist Ron Oesch, who died in 2012, with helping restore their prairie. Although an expert on snails, Oesch’s prairie work focused on sowing the seeds of recovery.

“Ron would scatter native plant seeds on the bare spots where he had removed invasive thistles and other weeds,” Tom said. “And he identified so many land snails,” Cathy said, “that we were afraid to walk out the front door for fear of crushing some of the beautiful things.”

Past field trippers said they were impressed with the Aleys’ restoration work. Leah Swindler is a graduate of MWSU, one of Ashley’s former students. She recalled her first visit to the Aleys’ prairie.

“Tom explained the arduous process that they had to go through with overgrazing impacting the watershed,” she said. “I really loved what they were doing there, and I would love to do something like that.”

Cathy points out that they now permit rest-rotation grazing on 1,300 acres of their prairie and pastureland. This benefits a local cattle owner and helps maintain the prairie’s natural community.

With rest-rotation grazing, cattle are allowed only on small areas of the land for short periods of time, then they are moved so the native grasses and wildflowers can recover, she said.

Exploring the Cave

Most field trippers enter Tumbling Creek Cave through an entrance that is enclosed — almost armored — and locked.

“It keeps out vandals and wildlife, but it provides relatively easy access to field trippers,” Tom said.

We ducked our heads to descend narrow, twisting stairs. Once on the cave floor, we followed the cemented pathway. Our headlamps revealed speleothems, “cave decorations,” as Cathy calls them, eternally dripping from the ceiling, rising up from the floor, or appearing to bubble up from various surfaces.

We passed through large chambers, some flowing with water. When we got to the chamber where Ashley and his students have laid ceramic tiles to help with cavesnail monitoring, Tom reached into the water and picked one up.

“Nope,” he said. “I don’t see any today.”

One of the students Ashley trained to help with monitoring was MWSU invertebrate zoology student Shannon Brewer. She’s now Dr. Brewer, an assistant professor at Oklahoma State University in the Department of Natural Resources Ecology and Management. Her experience with monitoring and learning from the Aleys left a big impression.

“Tom has always been receptive to helping students,” she said. “He’s been like that in my career at OSU, too. I called him and said we need some recharge mapping. He said, ‘I’m pretty busy right now, but I’ll teach you.’ Not many people are like that. I think his sense of person, in addition to his expertise and ability to tell a good story, make him pretty influential to students.”

A Lasting Legacy

Tom is 80 and Cathy is 70. Clearly, they have become conservation giants in the minds of their clients, peers, students, and friends. And while they’re both still involved in daily operations, they’re also keenly aware of the biggest threat to Tumbling Creek Cave — time.

To ensure that the cave, its recharge area, and its natural community have dedicated caretakers long after they’re gone, the Aleys have established Tumbling Creek Cave Foundation. “Every thought and all our energy go into taking care of the cave and the animals in it,” Cathy said. “The foundation will receive all our assets.”

Ashley serves on the foundation’s board of directors. “We intend to keep the focus on education activities that relate to karst resources,” he said.

Board members, including retired USFWS ecologist Paul McKenzie, who wrote the rule for the cavesnail’s emergency listing as well as its federal recovery plan, have expertise in geology, biology, and financial management.

“There’s a lot that can be done in the future to help visiting groups experience a pristine glade habitat or a restored savanna, as well as the cave itself,” Ashley said.

The Aleys’ Conservation Timeline


Tom buys Tumbling Creek Cave to establish the Ozark Underground Laboratory (OUL) and research field station


Local real estate agent, Deb Walley, discovers the cavesnail while helping build the cave trail


Cavesnail Population estimated at 15,000


Cathy accepts field biologist job with OUL


Tom and Cathy marry


With 115 identified cave species, Tumbling Creek Cave becomes a National Natural Landmark


Missouri Western State University biology professor Dr. David Ashley starts monitoring the cavesnail


The Tumbling Creek Cavesnail Working Group forms


Monitoring finds no snails in survey area; USFWS adds cavesnail to endangered species list


USFWS approves cavesnail recovery plan


Tumbling Creek Cave Foundation (TCCF) is Established


TCCF and partners acquire and restore recharge area land and keep invasive ringed crayfish out of the cave


May monitoring estimates 900 cavesnails in the survey area


TCCF acquires 640 acres of prime forestland adjoining OUL property

A Life with Purpose

“The Aleys live life with a purpose,” said MDC Fisheries Biologist Dave Woods. “They have dedicated their lives and livelihoods to educate people about karst and to safeguard one of Missouri’s most amazing natural features. To me, that is the ultimate example of living life with a purpose. They have had a bigger influence on my life than they will ever know.”

Also In This Issue

Hunting Snipe and Rail
A waterfowl hunter’s solution to the late-summer doldrums.

This Issue's Staff

Editor - Angie Daly Morfeld

Associate Editor - Larry Archer

Staff Writer - Bonnie Chasteen
Staff Writer - Heather Feeler
Staff Writer - Kristie Hilgedick
Staff Writer - Joe Jerek

Creative Director - Stephanie Thurber

Art Director - Cliff White

Designer - Les Fortenberry
Designer - Marci Porter

Photographer - Noppadol Paothong
Photographer - David Stonner

Circulation - Laura Scheuler