News Release

50th Anniversary of Mammoth Cave and Flint Ridge Connection

Water from the Echo River surrounds Minnehaha Island, the site of the famed 1972 Flint Ridge-Mammoth Cave connection.

NPS Photo/ Jackie Wheet and Dave Bunnell

News Release Date: July 25, 2022

Contact: Molly Schroer, 270-758-2192

Mammoth Cave National Park will mark the 50th Anniversary of the Flint Ridge-Mammoth Cave connection with a special cave tour to the connection site and several public events in the park and local community. The anniversary will take place in early September, but advance cave tour tickets will go on sale Monday, August 1. 

On the morning of September 9, 1972, a team of six people from the Cave Research Foundation (CRF) entered a cave on the Flint Ridge side of the Green River Valley and traveled for twelve hours before they discovered a passageway that connected the Flint Ridge Cave System to Mammoth Cave. This connection earned Mammoth Cave the title of longest cave in the world.  At the time, the two cave systems totaled a length of 144.4 miles (232.39 km). Since this monumental discovery, Mammoth Cave has remained the longest cave in the world and has continued to grow through continued exploration. The cave is currently mapped at 420 miles (676 km).

“To mark the anniversary of the big connection, we are excited to team up with our partners, the CRF, to highlight this major milestone in the history of the park,” said Superintendent Barclay Trimble. “We are working together to offer a special cave tour that will take visitors to the actual site where the connection occurred. We are also collaborating with them on other opportunities for the public to learn about the important exploration, scientific discovery, and volunteer work CRF provides for us each year.”

The 50th Anniversary Connection Tour will take place on Friday, September 9 and Saturday, September 10 at 8:30 am and 1:45 pm CDT. The trip will concentrate on the history of the exploration of the Mammoth Cave System and will culminate in seeing where the CRF team joined the Flint Ridge System to the Mammoth Cave System. Several CRF cavers will lead and assist in the tour with National Park Service employees and will share stories of exploration and the connection effort.  

The tour is a unique experience for the public to see a part of Mammoth Cave that is not normally included on standard tour routes. The route will follow historic trails that are uneven and rocky, but no crawling or climbing is required. The four-hour tour is limited to individuals 16 and older. 

Tour tickets are $35 each, and will be available on Monday, August 1 on the Recreation.gov website. Advance ticket reservations are highly recommended as the number of participants on each tour will be limited. 

Other events planned for the anniversary celebration will take place from September 7-10. They include a day of hands-on activities in the park’s picnic area, the display of a large-scale map of Mammoth Cave at Caverna High School Gymnasium, and ranger led evening programs that will highlight the connection discovery, the CRF discovery team and partnership between the CRF and National Park Service.