• The Historic Entrance of Mammoth Cave

    Mammoth Cave

    National Park Kentucky

Rivers and Streams

Nature and Science

Green River

The Green and Nolin Rivers possess one of the most diverse fish (82 species) and invertebrate faunas (51 species of mussels) in North America. In addition to the mussels, there are approximately 200 species of benthic macroinvertebrates in these rivers. For these biological reasons, the Green River has been designated an "Outstanding Resource Water". As explained above, since Green River is the base-level stream for the Mammoth Cave System, it has crucial influence on the cave aquatic community since food supply and sediment transport are both affected. Normal flow of 16 miles of the Green River, 7 miles of the Nolin River, and many miles of cave streams in the park is retarded by a relict dam known as Lock and Dam #6. Habitats for 7 federally listed endangered aquatic species are seriously degraded through reduction of natural flow velocity and resultant siltation. The quality of recreational non-motorized boating is also seriously diminished by the 21 miles of pooled river within the park.

Did You Know?

Did You Know? - Mammoth Cave is the world's longest known cave.

Mammoth Cave is the world's longest known cave, with more than 400 miles of interconnected passages—so long that if the second and third longest caves in the world were joined together, Mammoth Cave would still be the planet's longest cave and have more than 100 miles left over!