History of the Frozen Niagara Cave Tour Route

NPS Photo/ Ashley Decker

The Frozen Niagara cave tour route is a one-mile underground trail within Mammoth Cave in Barren and Edmonson Counties, Kentucky. Managed by the National Park Service as part of Mammoth Cave National Park, hundreds of visitors travel along the Frozen Niagara cave tour route each day on guided tours. Between 2022 and 2023, the National Park Service implemented a comprehensive cave trail improvement project along this route to provide a safer, more durable trail that can hold up to the footsteps of thousands of visitors every year while protecting sensitive natural and historic features of the cave.

First explored in the 1920s by entrepreneur George Morrison, tourists have been walking along the Frozen Niagara cave tour route to see its extraordinary geological formations for over a century. Development of the cave trail from a natural cave passage with a rocky, uneven ground into a more comfortable tourist trail can be grouped into four major developmental periods:

• The discovery and early tours by George Morrison in the 1920s.
• The trail construction by the Civilian Conservation Corps for creation of Mammoth Cave National Park in the 1930s.
• The modernization of visitor facilities of the Mission 66 Program in the 1950s and 1960s.
• The comprehensive trail rehabilitation undertaken by the National Park Service in 2022-2023.

Niagara Falls Frozen in Onyx

This narrative and visual history of the Frozen Niagara cave tour route, developed through the cooperation of Mammoth Cave National Park and the Kentucky Heritage Council, chronicles the history of the Frozen Niagara cave tour route and Mammoth Cave system.

Niagara Falls Frozen in Onyx [PDF 35 MB]