Stalactites and stalagmites line the floors and ceilings of Mammoth Cave. (Credit: NPS)

National parks, sometimes called the greatest idea and always best thought of as the gifts that keep giving, have been well covered in our pages.

Protecting them, beyond what their legal status provides has been a sub-theme. Today, a story with a different niche of a sub-theme, pointing to the longest cave system in the world, protected by park status:

(Credit: NPS)

50 Years Ago, Cavers Connected Mammoth Cave and Flint Ridge

The half-century anniversary marks the connection that established Mammoth Cave as the longest cave in the world.

Mammoth Cave’s historic entrance is a natural opening that has been used by humans for 5,000 years. (Credit: NPS)

It was the summer of 1972, and Tom Brucker was in a tight spot two generations in the making. His father Roger had created a nonprofit dedicated to the research of caves (aptly named the Cave Research Foundation) alongside colleagues who were exploring the Floyd Collins Crystal Cave in the 1950s — one of the main gateways to the Flint Ridge Cave System. Two decades later, the younger Brucker was squeezing through an extremely narrow passage deep inside Flint Ridge, considered the longest cave system in the world at the time, in an effort to see if it might connect with the similarly spectacular and storied Mammoth Cave system.

In an earlier expedition that summer, cave explorer Patricia Crowther had already made it through the same tight spot — a roughly 35-foot-long passage that stood near the end of what was then thought to be the longest stretch of the Flint Ridge system. Crowther had come to a waterfall tumbling down a pit at the end of the squeeze, but lacked the equipment at the time to continue.  

Roger and Tom Brucker returned in a subsequent expedition with others, and Tom was the right dimensions to wriggle through, though it took him half an hour to do so. “My father couldn’t fit through the initial squeeze, so I went through,” Tom says. He then made it down the waterfall and through a winding passage, eventually coming to a river and following it for 500 meters before turning back. Still, that progress was the first step in extending the longest known cave in the world.

The Wrong Way to the Right Destination

The explorers came back again; this time, four of them made it through. But the clock was ticking — for the sake of safety, they had a strict time limit. But they pressed on a little farther, following the river until they arrived at a room where they encountered a signature on the wall inscribed by Pete Hanson — an explorer active decades earlier — next to an arrow.  

Cavers usually use these arrows to point the way out of deep passages in case someone gets lost. But this arrow was pointing the opposite way from where Crowther’s team had just come. “We saw that and we were very, very excited, because we know we were most likely in Mammoth Cave,” Brucker says. Crowther continued on until she reached a point where the river came up to the ceiling of the cave. By that point, the cavers were way over their time limit, and they all turned back.

On September 9, 1972, explorer John Wilcox made it through the underground river when he saw that the water level had lowered. He made it through to Echo River, where he could see the Mammoth Cave’s main tourist trail. That initial discovery by Crowther and Brucker was now confirmed — the Flint Ridge Cave System, which was already the longest cave system in the world, connected to Mammoth, earning Mammoth Cave the title.

“The world’s longest cave became the world’s even longer cave,” says Brucker, who has spent his life caving just like his father. “Eventually the connection became known as the Everest of speleology.”  ...

Read the whole article here.