Horseshoe Lake , a National Natural Landmark

National Natural Landmark

The National Natural Landmark program recognizes and encourages the conservation of outstanding examples of the natural history of the United States. It is the only natural areas program of national scope that identifies and recognizes the best examples of biological and geological features in...

, is located in the American Bottom

American Bottom

The American Bottom is the flood plain of the Mississippi River in the Metro-East region of Southern Illinois, extending from Alton, Illinois, to the Kaskaskia River. It is also sometimes called "American Bottoms". The area is about , mostly protected from flooding by a levee and drainage canal...

 of Illinois

Illinois

Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...

 within the greater St. Louis

St. Louis, Missouri

St. Louis is an independent city on the eastern border of Missouri, United States. With a population of 319,294, it was the 58th-largest U.S. city at the 2010 U.S. Census. The Greater St...

 metropolitan area, is 2400 acres (10 km²) in size, and is the second-largest natural lake in Illinois after Lake Michigan

Lake Michigan

Lake Michigan is one of the five Great Lakes of North America and the only one located entirely within the United States. It is the second largest of the Great Lakes by volume and the third largest by surface area, after Lake Superior and Lake Huron...

. An oxbow lake

Oxbow lake

An oxbow lake is a U-shaped body of water formed when a wide meander from the main stem of a river is cut off to create a lake. This landform is called an oxbow lake for the distinctive curved shape, named after part of a yoke for oxen. In Australia, an oxbow lake is called a billabong, derived...

 which is a remnant of a Mississippi River

Mississippi River

The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...

 meander, the lake's elevation is 403 feet (123 m) above sea level

Sea level

Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...

. The lake is the site of Horseshoe Lake State Park

Horseshoe Lake State Park

Horseshoe Lake State Park is an Illinois state park in Madison County, Illinois, United States. It is approximately and surrounds a large horseshoe shaped lake called Horseshoe Lake. Horseshoe Lake is the second largest natural lake in Illinois taking up approximately 2400 acres of the park...

, which is 2960 acres (12 km²) in size. The lake is bordered by the towns of Madison

Madison, Illinois

Madison is a city in Madison County and partially in St. Clair County, Illinois, United States. The population was 4,545 at the 2000 census. It is home to Gateway International Raceway and the first Bulgarian Orthodox church in the United States.-Geography:...

 and Granite City

Granite City, Illinois

Granite City is a city in Madison County, Illinois, United States, part of the Greater St. Louis metropolitan area. At the 2010 census, the population was 29,849, making it the third largest city in the Metro-East and Southern Illinois, behind Alton and Belleville...

; it is located within Nameoki Township

Nameoki Township, Madison County, Illinois

Nameoki Township is located in Madison County, Illinois. The population was 11,186 at the 2000 census.- External links :****...

, about four miles east of St. Louis, Missouri

St. Louis, Missouri

St. Louis is an independent city on the eastern border of Missouri, United States. With a population of 319,294, it was the 58th-largest U.S. city at the 2010 U.S. Census. The Greater St...

.

The lake is very shallow, about three feet (1 m) deep throughout most the lake. There is however one deep spot, about 54.5 feet (16 m) deep, due to dredging for sand in years past. The lake is annually drained in part to provide shorebird habitat. At least 284 bird species have been found at this lake, which includes most of the species found statewide. Canada Geese

Canada Goose

The Canada Goose is a wild goose belonging to the genus Branta, which is native to arctic and temperate regions of North America, having a black head and neck, white patches on the face, and a brownish-gray body....

 winter here, as well as Bald Eagle

Bald Eagle

The Bald Eagle is a bird of prey found in North America. It is the national bird and symbol of the United States of America. This sea eagle has two known sub-species and forms a species pair with the White-tailed Eagle...

s. Other prominent birds include the Mallard duck, Snowy egret

Snowy Egret

The Snowy Egret is a small white heron. It is the American counterpart to the very similar Old World Little Egret, which has established a foothold in the Bahamas....

 and Little Blue Heron

Little Blue Heron

The Little Blue Heron, Egretta caerulea, is a small heron. It breeds from the Gulf states of the USA through Central America and the Caribbean south to Peru and Uruguay. It is a resident breeder in most of its range, but some northern breeders migrate to the southeastern USA or beyond in winter...

, and the Eurasian Tree Sparrow, limited to this region in North America. Fish species include Bluegill

Bluegill

The Bluegill is a species of freshwater fish sometimes referred to as bream, brim, or copper nose. It is a member of the sunfish family Centrarchidae of the order Perciformes.-Range and distribution:...

, Sunfish

Lepomis

Lepomis is a genus of freshwater fish in the sunfish family of order Perciformes. The most recognizable species of the sixteen in this genus is the Bluegill....

, Shortnose Gar

Shortnose gar

The Shortnose Gar is a primitive freshwater fish of the family Lepisosteidae.Shortnose gar have a prehistoric looking appearance. Like many other "lie-in-wait" predators, gars have an elongated, torpedo-like body with an elongated head containing one row of sharp, conical teeth...

, Spotted Gar

Spotted gar

The spotted Gar is a primitive freshwater fish of the family Lepisosteidae, native to North America from the Lake Erie and southern Lake Michigan drainages south through the Mississippi River basin to Gulf Slope drainages, from lower Apalachicola River in Florida to Nueces River in Texas, USA. It...

, Crappie

Crappie

Crappie is a genus of freshwater fish in the sunfish family of order Perciformes. The type species is P. annularis, the white crappie...

, Largemouth bass

Largemouth bass

The largemouth bass is a species of black bass in the sunfish family native to North America . It is also known as widemouth bass, bigmouth, black bass, bucketmouth, Potter's fish, Florida bass, Florida largemouth, green bass, green trout, linesides, Oswego bass, southern largemouth...

 and Channel catfish

Channel catfish

Channel catfish, Ictalurus punctatus, is North America's most numerous catfish species. It is the official fish of Missouri, Iowa, Nebraska, Kansas, and Tennessee, and is informally referred to as a "channel cat". In the United States they are the most fished catfish species with approximately 8...

. The western part of the lake is industrialized, dominated by the Granite City Works facility of United States Steel Corporation.