Lewis and Clark began their famous expedition from this area on October 26, 1803. Almost 400 million years ago, during the Devonian age, future states Indiana and Kentucky were asleep beneath a warm tropical sea, located about 20 degrees south of the equator. Shifting continents eventually moved these places to their present location, bringing an important souvenir of the past—a fossilized coral reef that extends from Louisville to Indianapolis. The reef is exposed only in the Falls of the Ohio, cascading rapids that tumble over a 2.5 mile stretch and formed a navigational barrier to early travelers on the Ohio. More than 600 fossil species of animals have been identified at the site. During the 45 million year span of the Devonian age, layers of lime silt, sediments, and plant and animal remains were deposited at the Falls. Among the living wildlife at the park are 265 species of birds and 125 species of fish, including some that are descendants from the age of the dinosaur. George Rogers Clark, John James Audubon, and Mark Twain sojourned to the Falls, and Walt Whitman wrote of his boat grating on the rocks.
