In the 19th century, Mammoth Cave in Kentucky was one of the most popular tourist destinations in America. Wealthy travelers arrived by stagecoach, train and steamship to tour the snaking passageways and domed chambers of this underground marvel, still the largest cave system in the world.

For the poor families of Appalachia, there was life-changing money to be made in operating a “show cave.” Those prospects fueled fierce competition to find and promote new caves. By the 1920s, there were dozens of show caves in the Mammoth region and operators often resorted to underhanded tactics to compete for tourist dollars.

Along the road to Mammoth Cave, uniformed cave promoters called “cappers” deployed charm—and misdirection—to siphon unwitting tourists away from Mammoth. They posed as policemen. They claimed that Mammoth Cave was closed or quarantined. In the worst cases, competitors burned down ticket booths, blocked access roads and even vandalized caves.

The “Cave Wars” of Kentucky raged for decades and were fought in the courtroom as well as on country roads. The ruthless competition was one of the main reasons why Mammoth Cave became a national park in 1941.

Mammoth Cave was known for millennia to the Indigenous people of Kentucky, who explored and occasionally occupied its chambers. White pioneers found the cave in the 1790s and almost immediately began guiding visitors through its impressive, open passageways. During the War of 1812, Mammoth Cave was mined for saltpeter (potassium nitrate), one of the main ingredients of gunpowder.

When demand for saltpeter waned, the private owners of Mammoth Cave developed it as a tourist attraction in the mid-19th century. Some of the most knowledgeable guides and bravest explorers of Mammoth were enslaved men like Stephen Bishop, who mapped the underground labyrinth by memory.

Before train lines were extended to Cave City in the 1880s, well-heeled travelers made the long journey to Mammoth Cave by stagecoach.

“It was a resort for the wealthy back in the 19th century,” says David Kem, author of The Kentucky Cave Wars: The Century that Shaped Mammoth Cave National Park. “If you could travel all the way to the middle of nowhere, spend a week at a hotel and play in a cave, you had to have some money.”

For local families, life in Appalachian Kentucky was a hardscrabble existence. When moneyed tourists started showing up to see Mammoth Cave, they provided an economic lifeline for the community, but only if they could get a piece of the action.

“It was a meager living around Mammoth Cave unless you found your way into the tourism business,” says Kem. “And that's really what drove the competition. That's where the money was. That's where the opportunity was.”

Thanks to the Mammoth region’s unique geology—known as karst topography—there are limestone caves everywhere in Kentucky. But simply having a hole in your backyard wasn’t enough to compete in the Cave Wars, says Kem. First, there had to be something worth seeing in the cave, like stalactites and sparkling mineral deposits. But more than anything, location was key.

Early Mammoth competitors like Diamond Caverns, Indian Cove and Hundred Dome Cave were successful because they offered small, showy caves located along the main stagecoach route to Mammoth. When the Mammoth Cave Railroad opened in 1886, the only way to compete was to have a cave with its own stop on the rail line.

Then, the arrival of automobiles in the early 20th century became a boon for cave entrepreneurs.

“The automobile was the death knell for the Mammoth Cave Railroad, but once people were in their cars, suddenly there were several dozen caves that were competing with Mammoth,” says Kem.

What the upstart cave promoters quickly learned was that people didn’t travel halfway across the country or even the world to see some unknown cave down a rocky dirt road. They came to see Mammoth Cave. And to compete with Mammoth, you needed a cave that connected with Mammoth.

“That was the holy grail—to find a backdoor to Mammoth Cave,” says Kem.

Even today, geologists don’t know the full extent of Mammoth Cave. More than 400 miles have been explored, but an estimated 600 more miles have yet to be mapped. A century ago, enterprising spelunkers were desperate to find a link to Mammoth Cave that extended beyond the legal boundaries of the Mammoth Cave Estate.

Knowing this, the owners of Mammoth Cave put a moratorium on mapmaking. No one was allowed to enter with paper, compasses or surveying equipment. Despite the ban, competitors were able to get their hands on an old 1871 map showing that Mammoth Cave ran beneath nearby ridges that were definitely not part of the Mammoth Cave Estate. That was the best chance to find a backdoor.

Colossal Cavern, opened at the turn of the 20th century, made the first serious attempt to breach Mammoth Cave. Colossal Cavern was an impressive cave in its own right—nearly equal in size to Mammoth at the time—but its owners had bigger plans. Backed by corporate investors and railroad money, they tried to blast their way into Mammoth and open a lucrative second tourist entrance to the world-famous cave.

“They never found it,” says Kem. “The dig hit the side of a valley and the dream of Colossal Cavern more or less fizzled. They didn't realize how close they were to making a connection.”

Others learned from Colossal Cavern’s mistakes, though. George Morrison was a struggling Louisville oilman who set his sights on another kind of underground treasure. Instead of blindly trying to break his way into Mammoth Cave, Morrison worked from the inside out. He explored the farthest reaches of Mammoth in search of an undiscovered exit that could become his new entrance.

“He actually broke into the cave,” says Kem. “Morrison bribed a guide, got a copy of the key and started exploring and surveying cave passages after hours and eventually found his way out.”

When the deal fell through to buy the land around his new entrance, Morrison didn’t give up. He rallied investors, purchased land in another promising location, and finally blasted his way back into Mammoth Cave. In 1922, Morrison opened his “New Entrance to Mammoth Cave” and that’s when the Cave Wars really heated up.

“To the owners of Mammoth Cave, it certainly felt like a war,” says Kem. “The competition was closing in around them and everybody was trying to steal their business.”

By the mid-1920s, the road from Cave City, Kentucky to Mammoth Cave was lined with “information booths” manned by competing caves. If a driver didn’t stop, one of the “cappers” would hop onto the sideboard of the car and make his pitch on the move. “There’s a long line down at the old entrance to Mammoth Cave,” the capper might say. “Don’t you want to see a new part of Mammoth Cave that no one’s seen before?”

To fight back, the owners of Mammoth Cave took Morrison and his “New Entrance” to court, claiming he was illegally using Mammoth’s name. While that case dragged on, warning signs were posted reading, “Caution to Tourists: If you want to see the original and only Mammoth Cave … do not be fooled by a so-called New Entrance!”

“It was a frustrating time to be a tourist, because you were given a lot of—if not direct misinformation—a lot of very confusing information,” says Kem. “Of course, all of the cave names sounded the same; that was intentional. There was Mammoth Onyx Cave, Onyx Cave, Great Onyx Cave, Crystal Onyx Cave. The list goes on and on. They were trying everything to drive people to their business.”

Good-natured competition among the cappers sometimes turned ugly. Access roads were damaged or blocked with boulders. At least one cave owner allegedly offered a $2 cash reward for destroying a rival’s sign. Burning down an information booth was worth $10. In 1921, an argument between two employees from competing caves ended with one man shot dead.

The Cave Wars became front-page news in 1925 when a Kentucky man named Floyd Collins became hopelessly trapped in Sand Cave. Collins was a skilled caver whose family homestead was just miles from Mammoth Cave. A few years earlier, Collins and his parents had sunk their savings into a failed operation called Crystal Cave. He hoped that Sand Cave would be different.

Instead, Collins became trapped in a narrow shaft deep underground when a rock fell and pinned his legs. His torturous ordeal ballooned into a media circus. Powered by the then-new technology of radio, reporters sent breathless dispatches from Cave City, where crowds of gawkers assembled in a carnival-like atmosphere.

When Collins’ lifeless body was finally pulled from the cave 18 days later, the tragedy could have brought an end to the Cave Wars, but it didn’t.

“Thanks to Floyd's death, there was a new low that people were willing to sink to in order to pull in tourists,” says Kem. “It really signaled a dark turn in the Cave Wars.”

In 1927, the new owners of Crystal Cave paid Collins’ family to exhume his body and put it on display in a glass-topped coffin inside the cave. The grotesque attraction became a popular stop on the Mammoth tourist circuit.

When Mammoth Cave was turned into a national park in 1941, federal management of the site was supposed to end the Cave Wars, but it created other problems instead, says Kem.

“We celebrate the fact that Mammoth is a national park now and that we can share that with the world, but there were hundreds of local families that were forcibly removed from their land to make that happen.”

By the 1960s, most of the privately-owned caves shut down, no longer able to compete with the draw of Mammoth Cave National Park. One exception is Diamond Caverns, which has been in continuous operation since 1859. Today, Mammoth Cave attracts more than 600,000 visitors every year and stands as a testament to Earth's geological marvels.