Mammoth Cave underground view, ca. 1935.
Mammoth Cave, Mammoth Cave National Park, Edmonson County, Kentucky, USA
The Onyx Colonnade, New Entrance underground Mammoth Cave , ca. 1935. Vintage picture postcard, published by Caufield & Shook, Inc., Louisville.
G. Grundmann collection.
© Caufield & Shook, Inc., Louisville.