The Falls of the Ohio National Wildlife Conservation Area is a national, bi-state area on the

Ohio River The Ohio River is a long river in the United States. It is located at the boundary of the Midwestern and Southern United States, flowing southwesterly from western Pennsylvania to its mouth on the Mississippi River at the southern tip of Illino ...

near

Louisville, Kentucky Louisville ( , , ) is the largest city in the Commonwealth of Kentucky and the 28th most-populous city in the United States. Louisville is the historical seat and, since 2003, the nominal seat of Jefferson County, on the Indiana border ...

in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

, administered by the

U.S. Army Corps of Engineers , colors = , anniversaries = 16 June (Organization Day) , battles = , battles_label = Wars , website = , commander1 = ...

Federal Federal or foederal (archaic) may refer to: Politics General *Federal monarchy, a federation of monarchies *Federation, or ''Federal state'' (federal system), a type of government characterized by both a central (federal) government and states or ...

status was awarded in 1981. The falls were designated a

National Natural Landmark The National Natural Landmarks (NNL) Program recognizes and encourages the conservation of outstanding examples of the natural history of the United States. It is the only national natural areas program that identifies and recognizes the best ...

in 1966.

Overview

The area is located at the Falls of the Ohio, which was the only navigational barrier on the river in earlier times. The falls were a series of rapids formed by the relatively recent erosion of the Ohio River operating on 386-million-year-old

Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...

hard

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

rock shelves.

, and the associated

Indiana Indiana () is a U.S. state in the Midwestern United States. It is the 38th-largest by area and the 17th-most populous of the 50 States. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th s ...

communities— Jeffersonville, Clarksville, and New Albany—all owe their existence as communities to the falls, as the navigational obstacles the falls presented meant that late-18th-century and early- to late-19th-century river traffic could benefit from local expertise in navigating the drop made by the river over a distance of two miles (3 km). In its original form, the falls could be characterized more as rapids extending over a length of the river, than as a point-like discontinuity in a river such as

Niagara Falls Niagara Falls () is a group of three waterfalls at the southern end of Niagara Gorge, spanning the border between the province of Ontario in Canada and the state of New York in the United States. The largest of the three is Horseshoe Falls, ...

. Still, the falls provided a singular, dramatic and daunting obstacle to navigation on this important

inland waterway A body of water, such as a river, canal or lake, is navigable if it is deep, wide and calm enough for a water vessel (e.g. boats) to pass safely. Such a navigable water is called a ''waterway'', and is preferably with few obstructions against dir ...

. The first locks on the river, the

Louisville and Portland Canal The Louisville and Portland Canal was a canal bypassing the Falls of the Ohio River at Louisville, Kentucky. The Falls form the only barrier to navigation between the origin of the Ohio at Pittsburgh and the port of New Orleans on the Gulf of Mex ...

completed in 1830, were built within a bypass canal constructed to provide year-round navigation of the river. The falls were later largely covered by the

McAlpine Locks and Dam The McAlpine Locks and Dam are a set of locks and a hydroelectric dam at the Falls of the Ohio River at Louisville, Kentucky. They are located at mile point 606.8, and control a long navigation pool. The locks and their associated canal were the ...

, built by the Army Corps of Engineers. The taming of the Ohio River at the falls, with the attendant reduction in local flow velocity, has of late led to the covering over of the

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

beds by large and increasing quantities of low-velocity effluvia: although an impediment to viewing of the fossils, this action serves to protect the portions of the falls covered over by sediment and therefore temporarily immune to direct weathering. However, a significant area of the fossil-rich Devonian limestone rock is still left exposed, and is accessible to visitors today. The best time for visitation is during the low water season of the Ohio River between August and October. Removal of fossils is prohibited. The shallowness of the falls provided a favored crossing point for

bison Bison are large bovines in the genus ''Bison'' (Greek: "wild ox" (bison)) within the tribe Bovini. Two extant and numerous extinct species are recognised. Of the two surviving species, the American bison, ''B. bison'', found only in North Ame ...

in pre-settlement times and, later, an easy crossing for Native Americans. In 1990, a section of the area in Indiana became the

Falls of the Ohio State Park Falls of the Ohio State Park is a state park in the U.S. state of Indiana. It is located on the banks of the Ohio River at Clarksville, Indiana, across from Louisville, Kentucky. The park is part of the Falls of the Ohio National Wildlife Conserv ...

. An

interpretive center An interpretation centre, interpretive centre, or visitor interpretive centre is an institution for dissemination of knowledge of natural or cultural heritage. Interpretation centres are a kind of new-style museum, often associated with visitor c ...

is open throughout the year.

Size and sound

Prior to modification for industrial and navigational purposes, the Falls of the Ohio spanned the entire width of the Ohio River. Native Americans and early European explorers heard the crisp roar of the Ohio River crashing down the cascade falls more than 10 miles away.

Geology

The rock unit in which the falls are formed is referred to as the Jeffersonville

. The limestone formed approximately 387 to 380 million years ago during the

Emsian The Emsian is one of three faunal stages in the Early Devonian Epoch. It lasted from 407.6 ± 2.6 million years ago to 393.3 ± 1.2 million years ago. It was preceded by the Pragian Stage and followed by the Eifelian Stage. It is named after the ...

Age (in the latest part of the Early

Period) and the

Eifelian The Eifelian is the first of two faunal stages in the Middle Devonian Epoch. It lasted from 393.3 ± 1.2 million years ago to 387.7 ± 0.8 million years ago. It was preceded by the Emsian Stage and followed by the Givetian Stage. North American ...

Age (Middle Devonian). The exposure is unique—large and diverse

tabulate coral Tabulata, commonly known as tabulate corals, are an order of extinct forms of coral. They are almost always colonial, forming colonies of individual hexagonal cells known as corallites defined by a skeleton of calcite, similar in appearance to ...

s and

rugose corals The rugosa, also called the tetracorallia or horn coral, are an extinct order of solitary and colonial corals that were abundant in Middle Ordovician to Late Permian seas. Solitary rugosans (e.g., '' Caninia'', '' Lophophyllidium'', '' Neoza ...

are exposed in lifelike positions.

Brachiopod Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, w ...

s and

bryozoa Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about long, they have a special feeding structure called a l ...

ns are also present, as are

gastropods The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. Ther ...

(snails). During the Devonian Period, the region lay at the bottom of a shallow inland sea about ten degrees north of the equator in the

supercontinent In geology, a supercontinent is the assembly of most or all of Earth's continent, continental blocks or cratons to form a single large landmass. However, some geologists use a different definition, "a grouping of formerly dispersed continents", ...

Euramerica Laurasia () was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around ( Mya), the other being Gondwana. It separated from Gondwana (beginning in the late Triassic period) during the breakup of Pan ...

References

External links

Falls of the Ohio State Park

Falls of the Ohio Archaeological Society

Falls of the Ohio
(U.S. Army Corps of Engineers). Retrieved 29 April 2017 * * *

(surveyed by Capt. T.J. Cram, Summer 1843) * * {{authority control Clarksville, Indiana History of Louisville, Kentucky Landforms of Louisville, Kentucky Ohio River

Ohio Ohio () is a state in the Midwestern region of the United States. Of the fifty U.S. states, it is the 34th-largest by area, and with a population of nearly 11.8 million, is the seventh-most populous and tenth-most densely populated. The sta ...

Tourist attractions in Louisville, Kentucky Protected areas of Clark County, Indiana Protected areas of Jefferson County, Kentucky National Natural Landmarks in Indiana National Natural Landmarks in Kentucky Waterfalls of Indiana 1981 in paleontology Protected areas established in 1981 1981 establishments in Kentucky 1981 establishments in Indiana

Overview

Size and sound

Geology

See also

References

External links