Mammoth Cave National Park may be getting more mammoth.

A bill to expand the park boundaries by more than 500 acres was introduced in Congress last week.

The Mammoth Cave National Park Boundary Adjustment Act would give the Secretary of the Interior the ability to acquire an additional 551.14 acres of land currently owned by the Nature Conservancy.

The Nature Conservancy is a global environmental nonprofit. No details, such as the cost of the land, is detailed in the act.

This newly acquired land would enhance protections in the Green River watershed, further conserving the area’s wildlife and cultural heritage while generating additional tourism to Kentucky’s Second District, according to a news release from Rep. Brett Guthrie and Sen. Mitch McConnell.

The additional property includes cave passages, including Coach and James Caves, which hold prehistoric and historic artifacts, and the expansion would allow the park to manage land in Edmonson and Barren counties.

Sandra Wilson, executive director of Horse Cave/Hart County Tourism, said that tourism income has been a part of the economies of the Mammoth Cave gateway communities for over 200 years.

“Because we are located in a sensitive karst terrain area, the Green River watershed has a critical impact on our communities, as well,” she said.

“Every year, Mammoth Cave National Park draws hundreds of thousands of visitors and contributes nearly $90 million to our local economy,” Guthrie said in the news release. “This natural wonder has inspired people for thousands of years, playing a foundational role in the culture of our region. I am proud to introduce the Mammoth Cave National Park Boundary Adjustment Act to expand protections for the cave system’s important biodiversity and rich history, ensuring that it can be studied, maintained and enjoyed by future generations of Americans.”

“Kentucky is lucky to be home to an abundance of natural treasures, among them, Mammoth Cave National Park. This extensive cave network has been inspiring Kentuckians and drawing visitors from all corners of the globe for generations. Beyond its role in driving tourism to our commonwealth, the park also plays a crucial role in the region’s economic growth, supporting good jobs for the people of Kentucky,” McConnell said in the news release.

“I’m proud to partner with Congressman Guthrie on this important initiative once again which will expand the critical habitats that the National Park Service protects and preserves in the park.”

— A map of the proposed boundary changes can be found at https://guthrie.house.gov/uploadedfiles/2025_mcnp_maca_legmap135_177967_20250507.pdf