Hidden River Cave
The nonprofit American Cave Conservation Association (ACCA) operates Hidden River Cave and the American Cave Museum as part of our educational initiative to support the protection of caves, karstlands, and groundwater resources.
— John Muir’s visit in 1867
Thousand Mile Walk to the Gulf
— John Muir’s visit in 1867
Thousand Mile Walk to the Gulf
Hidden River Cave: An Environmental Success Story
Hidden River Cave is located directly beneath the City of Horse Cave in south central Kentucky. Its main entrance is at 119 East Main Street in the center of town! Hidden River Cave and the American Cave Museum are operated by the American Cave Conservation Association (ACCA), a national nonprofit organization committed to the protection of caves, karstlands and groundwater.
The cave was once the source of drinking water and hydroelectricity for the City of Horse Cave and offered commercial tours from 1912 through 1943. Groundwater pollution from domestic and industrial sewage, combined with the impact of low visitation during World War II and a lawsuit by the L&N Railroad led to the cave’s closing in 1943. For 50 years Hidden River Cave had been all but forgotten except during hot summer months when noxious fumes spewed from its enormous entrance.
In 1987 the American Cave Conservation Association relocated their national headquarters from Richmond, Virginia to Horse Cave at the invitation of William T. (Bill) Austin. Bill had approached two other caving organizations about creating an educational center at Horse Cave without success. As fortune would have it, ACCA was looking for a new home and jumped at the opportunity.
A planning grant from the Economic Development Administration provided funding for a feasibility study and Horse Cave seemed like the perfect place for a national cave and karst center. The site was in an internationally significant cave area near Mammoth Cave National Park, the educational and environmental needs were obvious: a polluted cave right in the middle of town, and the location was in a major tourism travel corridor. At this same time a new regional sewage treatment system was also being developed by the Caveland Sanitation Authority and hopes were high that this would correct the groundwater problems in the cave. In 1989, this system went online.
With sewage no longer draining into the cave, a remarkable recovery began to occur. ACCA continued to raise funds for exhibits and to operate the Karst Center. In 1992, the first phase of the center opened to the public as the American Cave Museum. Since that time, we have raised approximately 7.5 million dollars for land acquisition, construction of the museum, additional exhibits, developing the tour into Hidden River Cave and to fund our ongoing educational and conservation programs.
Today, thousands of visitors and school children tour Hidden River Cave and the American Cave Museum. The museum and the cave, which has been called “the greatest cave restoration success story in the United States” is now open year-round to visitors.
An Early Source of Water and Electricity
The Village of Horse Cave was founded around 1850 on land surrounding the scenic entrance to Horse Cave. Before the modern era, native Americans and later, white settlers, made their homes around this good source of water.
As early as 1879, attempts were made to set up public waterworks in the cave. Not only did the cave stream provide drinking water, it later provided the necessary force to boost water into towering supply tanks that held water for fighting fires.
In 1888, Dr. George A. Thomas moved to Horse Cave to establish a dental practice. He purchased a house by the cave entrance and a year later purchased the cave for $375.00. He envisioned the cave as a source of both water and electrical power. Water from a spring in the north wall of the cave entrance was caught in a wooden tub and hauled up to a brick springhouse by a clever bucket trolley. Later, the south branch of the cave stream itself became the source of water for the town and the power to lift it to a standpipe located on the lip of the cave entrance.
The Show Cave Era
In 1916, a half mile-long section of Horse Cave was opened to the public for tours. As part of a promotion Dr. H.B. Thomas ran a local contest to rename the cave, and the name “Hidden River Cave” was chosen for tourist use. Hidden River boasted elegant galleries and offered scenic tours along the river’s winding course through the cave. One of the tour’s most distinctive features, “Sunset Dome,” is a room at the end of the tour that is approximately 250 feet in diameter and 100 feet tall. The cave which has yet to be fully explored, was home to a number or rare cave creatures, including a large population of blind cavefish and blind cave crayfish.
The Destruction of the Cave
Since the time the Horse Cave area was first settled local residents dumped their trash and injected sewage into underlying cave passages, shallow wells, and nearby sinkholes, never realizing that they were contaminating Hidden River Cave and their own water supplies. By the mid-1930s, the town’s water supply was hopelessly polluted, and in 1943 noxious odors emitted by the cave’s pollution caused the closure of the tours. In addition to domestic sewage, wastes from local industries caused serious pollution and depletion of the stream’s oxygen. In the 1950s, vile odors permeated the entire business district of Horse Cave during the summer months, and the cave life completely died out.
In 1963, the community constructed a domestic sewage treatment plant. Unfortunately, the wastewater from this plant was dumped into dry wells which funneled into Hidden River Cave. Over the next two decades, the cave’s pollution problem grew even worse. In 1975, thousands of gallons of gasoline were lost into the cave system from a leaking tank. The gasoline fumes could be smelled in many local basements.
The Cave’s Recovery
For several decades the grossly contaminated Hidden River Cave lay neglected and shunned by humans. The cave streams were void of life, except for strings of sewage bacteria and writhing bloodworms that thrived in the nearly oxygen-free underground waters. Gone were the once-plentiful blind cavefish that, like most animals adapted to living in cave streams, require highly stable conditions. The entrance to the cave was nearly invisible to passersby, surrounded by buildings, thick vegetation, and a high fence. It was easy to ignore the cave, except during each summer when the horrible stench of raw sewage belched from its mouth and reminded everyone of its presence.
The Opening of the American Cave & Karst Center
In 1992, cleanup efforts Hidden River Cave’s large sinkhole entrance began to restore the lush setting described by John Muir after his 1867 visit. Exploration and mapping of the cave also resumed under the leadership of the ACCA after a 50-year hiatus. The full extent of the passageways is still unknown. In addition, plans to reopen the cave were considered. The first stage was accomplished in 1992 by improving the steps and walkway to the underground river.
Also, in 1992, the American Cave and Karst Center was established in historic buildings at the mouth of Hidden River Cave, once again calling attention to this remarkable natural feature: remarkable for its unique setting, it’s inherent beauty, its quintessential geology, and the successful rejuvenation of its underground river system.
A New Century Dawns
In 2013, Dr. Julian J. Lewis began a biological inventory of Hidden River Cave. The study found that Hidden River Cave’s once polluted passages were now home to twenty-one types of cave species, making the cave a global hot spot of subterranean biodiversity. In two decades, Hidden River Cave had transformed from one of the most polluted to one of the most biologically diverse cave ecosystems in the world.
By 2015, groundwater studies conducted by researchers from Western Kentucky University and Canada’s McMasters University concluded that Hidden River Cave’s water quality had recovered to near drinking water standards.
Securing the Cave’s Protection
Although Hidden River Cave was an amazing success story, there were still a few complex obstacles to overcome to ensure its protection.
In the 1930s it became very clear that what goes on above ground can severely affect what happens below the ground. A local landowner had erected a gasoline station on a lot that was directly above part of Hidden River’s developed tourist trails inside the cave. He then began disposing of sewage from the station’s restrooms into a hole drilled into Hidden River Cave. To complicate matters, the landowner did not own the cave rights – these were owned by the L&N Railroad Company.
The Quest for Sunset Dome
With Hidden River Cave now an environmental success story and the protection that these new agreements put it place, work began to raise funds to construct the walkways and bridges into Sunset Dome. Funding came from the James Graham Brown Foundation, the Appalachian Regional Commission, the Dart Foundation and an anonymous gift from Friends of Bill Austin.
The first construction challenge was bridging the 50-foot-deep canyon that separated the end of the existing tour from Thomas Hall, the trunk passage leading to Sunset Dome. It was decided to build a 100-foot-long suspension bridge across the canyon. This would become the longest suspension bridge inside a cave in the entire world.
Thank You for Reading!
The story of Hidden River Cave is not only an environmental success story, it is a testament to the perseverance and faith of everyone involved from a small nonprofit that took the leap of faith to move their operations to Horse Cave, Kentucky with no tangible promise of success, to the many volunteers, community leaders and gracious foundations and agencies who supported and believed in this effort.
photo by Lisa Powers
Hidden River Cave & The American Cave Museum are operated by the American Cave Conservation Association,
A National 501 (c) 3 Nonprofit Organization.