Home to the world's longest known cave system, Kentucky's Mammoth Cave National Park has what river running through it?

The Green River in Kentucky is a tributary of the Ohio that runs almost 400 miles. Named after the Revolutionary War General Nathanael Greene, the river passes through the Mammoth Cave system at miles 188 to 210, drains the cave, and also controls the level of the water in the caves.

Asked by Tom Cohen · Last updated 5 years ago · 14.6K views