This image shows a tourist boat cruising through the waters of Echo River in Mammoth Cave.
The description states:
ECHO RIVER IN MAMMOTH CAVE
Mammoth Cave National Park, Kentucky
This famous cover stream is 360 feet beneath the surface. The subterranean boat ride is one of the outstanding attractions of Mammoth Cave. Eyeless Fish live in the waters of Echo River.
— The image is professionally lit, as there would not normally be a light in the middle of the boat illuminating the tourists’ faces. This image gives a very good idea of the size and type of boat commonly used in this era, the 1950s. It is being rowed by a National Park employee in uniform.