MAMMOTH CAVE, Kentucky — For thousands of years, people have ventured into the caves beneath the rolling hills of central Kentucky.
In the 1840s, Stephen Bishop, an enslaved Black guide, explored the vast system by lantern and drew one of the earliest maps.
More than 426 miles have since been surveyed, making Mammoth Cave National Park the world’s longest known cave system. It’s a landscape so unique that it has been designated both a UNESCO World Heritage Site and an International Biosphere Region.
Now, looming above this ancient world is a behemoth of the future.
Near Cave City, the tiny Kentucky town that serves as a gateway to the national park, developers are planning a $4.8 billion hyperscale data center across roughly 600 acres. At full build-out,
it could demand 1,200 megawatts of power, enough for more than 1 million U.S. homes, or more than half of all households in Kentucky.
The data center would be located about 10 miles from Mammoth Cave National Park's main visitor center, which draws hundreds of thousands of tourists each year.
And it has plunged Cave City, population roughly 2,400, into a legal battle with the developer over a yearlong data center moratorium. Residents have packed public meetings, staged protests and held prayer vigils against a project they fear could permanently change their home.
The fight mirrors battles playing out across the country as communities confront the enormous power and land demands of the artificial intelligence boom. Proponents of data centers, which house the computing infrastructure that powers AI and other digital services, point to jobs and tax revenue, while critics raise concerns about impacts on water, electricity and the environment.
Kentucky Industrial Alliance, which owns the proposed project site, did not respond to emails requesting comment. An economic review commissioned by the developer estimates the completed campus could generate billions in tax revenue and create hundreds of permanent jobs.
But Cave City has an unusual complication: Experts say the site sits within the vast groundwater system that feeds Mammoth Cave.
Kyle Groetzinger, a spokesperson for the National Parks Conservation Association, said the cave’s underground watershed makes this a particularly troubling place for such a massive project.
“The data center industry is scrambling, looking where they can put these projects,” he said. “But the community has really vocalized the reasons we care about Mammoth Cave. This isn’t the right place.”
What lies beneath
About 90 minutes north of Nashville, Mammoth Cave sits atop a landscape that hydrogeologist Chris Groves likes to compare to “Swiss cheese.”
Groves, a Western Kentucky University professor who has studied the cave system for decades, is concerned about what could happen above it.
The landscape is karst, porous limestone riddled with cracks and sinkholes. Rain can disappear underground and travel for miles, carrying pollution with it.
Groves has helped map those hidden pathways by pouring harmless fluorescent dyes into sinkholes and tracking where they reappear. That work has shown that more than 100 square miles south of Mammoth Cave National Park drain into underground rivers flowing toward the park and Green River.
The proposed data center project sits “well within this area,” Groves said.
That doesn't mean it would pollute Mammoth Cave. But Groves said the site's location warrants closer study to determine where a possible spill or contaminated stormwater could travel.
Below ground, the scale of what he wants protected comes into view.
On a recent weekday, visitors on a park history tour descended through a gaping natural entrance into echoing chambers, passing rusted vats from an 1812 mining operation beneath sweeping limestone domes. They squeezed sideways through the narrow passage known as Fat Man's Misery and passed thousands of 19th-century signatures written in candle soot.
“Man could never have built something this cool,” one visitor remarked.
The darkness also harbors species found in few other places, including the translucent, eyeless Kentucky cave shrimp and northern cavefish. Rare and endangered bats inhabit the caves, adding to concerns about how development could affect the environment.
And the porous landscape occasionally makes itself dramatically visible.
In 2014, a sinkhole opened beneath the National Corvette Museum in nearby Bowling Green and swallowed eight rare Corvettes.
Across the railroad tracks
Angie Herald's 40-acre family farm in Cave City sits against the proposed data center campus, separated only by train tracks.
Herald, 50, lives there with her children and parents, surrounded by rolling green farmland where she raises cows and chickens and cares for roughly two dozen rescue dogs. Her father has run a tire shop on the property for about half a century. Herald runs a consignment store.
Herald said she had no idea what was being planned until a Cave City councilwoman posted about the data center on social media.
Suddenly, she was confronting the possibility that a data center campus could become her family's neighbor.
And she began thinking about everything that could change.
The water they rely on. The quiet of the farm. The value of land she hopes her children will someday inherit.
“I want to keep this in my family,” Herald said.
What worries her most is what happens if the development changes the place permanently, but her family can't afford to leave.
“Another huge concern is the depreciation of our land,” she said. “If it comes, and it's as bad as they say, how do we sell?”
A town built around the cave
Cave City has spent generations making a living from the land below.
Roadside kitsch, antique shops and quirky attractions still cater to Mammoth Cave tourists, but an aging downtown is increasingly marked by empty storefronts.
Nearly 30% of residents live in poverty. And a project promising billions of dollars in investment could provide a significant economic boost.
Kentucky Industrial Alliance is working with tech infrastructure developer The OTN Group, but the data center's eventual owner and operator remains unknown. Its size resembles hyperscale campuses built by the world's largest tech companies.
An economic analysis commissioned by Kentucky Industrial Alliance for the project estimates the completed campus could generate $45.2 million a year in tax revenue and create 360 permanent jobs.
The development plans for a closed-loop cooling system requiring about 300,000 gallons of water a day, relatively little for a hyperscale data center.
Power is another matter. The campus could require 1,200 megawatts at full build-out, supplied by East Kentucky Power and a dedicated natural gas power plant built on-site.
Representatives of Kentucky Industrial Alliance and The OTN Group did not respond to emails requesting comment. But in a June 20 statement provided to local news outlets, Kentucky Industrial Alliance said the project would be subject to environmental regulations and permitting.
“The question should not be whether development occurs,” the statement read. “The question should be whether development can occur responsibly while protecting the natural resources that make our region unique.”
The company said concerns about groundwater and karst should be resolved through “science, engineering, and objective review.”
But a state environmental review has yet to begin.
The Kentucky Energy and Environment Cabinet said it has not yet received permit applications for the project. Depending on its final design, the development could require permits for stormwater, air emissions and impacts to waterways.
The state also requires data center projects to submit an energy plan under an executive order issued by Gov. Andy Beshear this year.
For Cave City officials, the unanswered questions were reason enough to hit pause.
The councilwoman who came home
Leticia Cline had already reinvented herself a few times before deciding to reinvent her hometown.
Born and raised in Cave City, she left Kentucky and spent years working as a model and television personality, racing motorcycles and even announcing professional wrestling before moving into public relations in New York.
When she came home, Cline set about trying to revive the downtown she remembered. She bought an old movie theater, renovated it into a cozy coffee shop and moved into an apartment upstairs. She helped open businesses and create gathering spaces before running for city council, where she is now serving her second term.
“I didn't want to live here, so I was like, ‘Well, I'm going to build the town I want to live in,’” she said.
Cline rejects the idea that opposing the data center means opposing economic development. She knows Cave City needs investment but argues that struggling communities can become too willing to accept whatever comes along.
“If you're starving, you're gonna eat a cracker and think it's steak,” she said.
This spring, Cline learned the city was considering new zoning rules that could clear the way for a massive data center.
She started researching and became convinced a project of that scale didn't belong anywhere near Cave City. Then she searched for a way to stop it, at least long enough for the city to decide what it was willing to allow.
Late one night, the answer came to her: “I sat up at 2 a.m. and thought: ‘Moratorium!’”
Cline had seen other cities use moratoriums to deal with short-term rentals. She decided Cave City could use the same tool for data centers.
She told no one what she was planning. Cline worried that if word got out, project supporters would arrive at the council meeting prepared to counter her proposal.
When the meeting came, she waited through the presentations, then proposed freezing new data center applications for a year while Cave City studied the industry and considered new rules.
After a series of special meetings in May, the council enacted the 12-month pause.
Then, Kentucky Industrial Alliance promptly sued the city.
A small town goes to court
Mayor Dwayne Hatcher declined to discuss the proposed development, saying only: “We are not dealing with any data centers. We are dealing with the landowner.”
That landowner, Kentucky Industrial Alliance, argued in court that its development plans were already under review when Cave City enacted the moratorium and should be considered under the previous rules. The city said the submission was incomplete and has asked a judge to dismiss the case.
Kentucky Industrial Alliance also sued over the city's 2024 annexation of property tied to the development. In August, a judge consolidated the two cases, which are due back in court Nov. 23.
For Cave City, the fight is getting expensive.
“My biggest concern is that we don't have enough money to fight it,” Cline said.
Cline said the city operates on a roughly $3.5 million annual budget and has spent about $15,000 on the litigation so far, with $10,000 covered by the Kentucky League of Cities. Cline said the city may finish a typical year with only about $20,000 to spare.
“It's really easy to get worn down in a town that's already hanging on by a thread,” she said.
Cave City isn't alone.
Similar fights are playing out across the country. Nashville's data center moratorium prompted a lawsuit over a proposed project near the Nashville Zoo, while in Virginia, developers abandoned a massive complex near Manassas National Battlefield Park after courts voided key rezonings.
Those battles are increasingly reaching the doorstep of protected lands. The National Parks Conservation Associationhas identified more than 70 park sites facing pressure from data center growth.
What Cave City leaves behind
The debate in Cave City now spans generations.
Trace Brooking, a 17-year-old junior at Glasgow High School, roughly 10 miles south of Cave City, knew little about data centers when he chose the topic for an AP Seminar project. Then he learned one of the nation's largest proposed campuses could be built near Mammoth Cave.
He began talking about the project with classmates and went to his first council meeting, where teenagers sat alongside residents old enough to be their grandparents.
“It's not a D or an R issue,” Brooking said. “It's something that affects the community.”
Brooking said he’s concerned about what kind of place his generation will inherit.
Cline worries about what a project of this scale could mean for the cave system, the surrounding environment and the small community she came home to rebuild.
And she sees Cave City confronting the same question now facing other communities: How much are they willing to change to accommodate the data center boom?
“I really thought ... there's no way that any idiot is going to try and put one next to Mammoth Cave,” she said.
Months later, with the project still alive and the city fighting in court, Cline said she has no intention of backing down.
“I'm here to be a voice. I was elected to be a voice of the people,” she said. “Why would I give up?”
Shifting Ground is an occasional series by The Tennessean examining how major development projects are reshaping communities.
From landfills and data centers to industrial facilities and energy projects, the series explores the promises of growth alongside concerns about land use, environmental impacts and quality of life. It follows the residents, businesses and public officials navigating those changes and the communities fighting to shape their own futures.
This article originally appeared on Nashville Tennessean: At Kentucky's Mammoth Cave, an ancient world meets the AI boom
