List of impact craters in North America
Unconfirmed impact craters
Table:
Name	Location	Diameter ( km )	Age ( years )	Probability

Alamo bolide impact	Nevada , USA	unknown	367 million

Bow City	Alberta	8 km	70 million

Corossol	Quebec	4 km	2.6 million

Decorah crater	Iowa , USA	5.6	470 million	2 ( probable )

Gatun structure	Panama	2.7-3.0	20 million	2 ( probable )

Pantasma	Nicaragua	10	1 million	4 ( not probable )

Jeptha Knob	Kentucky , USA	4.3	425 million	2 ( probable )

Panther Mountain	New York , USA	10	375 million	2 ( probable )

Snows Island	South Carolina , USA	11	unknown	2 ( probable )

Toms Canyon	New Jersey , USA	22	35 million	2 ( probable )

Victoria Island structure	California , USA	5.5	37-49 million	2 ( probable )

Weaubleau-Osceola	Missouri , USA	15-20	325.0 ± 15.0 million	2 ( probable )

Brushy Creek Feature	Louisiana , USA	2	11,000 - 30,000 years	2 ( probable )

From the table as well as the supporting text provided at the end.

Answer the following question: The crater that is 22 km wide was formed during which geological period of time ? Return your answer as JSON: {"answer": "YOUR ANSWER"}. Do not introduce information beyond the provided sources.

The Alamo bolide impact occurred 367 million years ago , when one or more hypervelocity objects from space slammed into shallow marine waters at a site that is now the Devonian Guilmette Formation of the Worthington Mountains and Schell Creek Range of southeastern Nevada ; the event is named for breccias of metamorphosed crushed rock deposits , found as far as the town of Alamo , Nevada ( the Alamo Breccia ) . This catastrophic impact event resulted in what is one of the best-exposed and has become the most accurately dated impact events ; it occurred within the Frasnian age of the Devonian at about 367 Ma , a moment in time that was about 3.5 Ma prior to the Frasnian/Famennian extinction events , which it is unlikely to have affected .
Nevada ( /nɪˈvædə/ or /nɪˈvɑːdə/ ) is a state in the Western United States . It is bordered by Oregon to the northwest , Idaho to the northeast , California to the west , Arizona to the southeast , and Utah to the east . Nevada is the 7th most extensive , the 32nd most populous , and the 9th least densely populated of the U.S. states . Nearly three-quarters of Nevada 's people live in Clark County , which contains the Las Vegas-Paradise metropolitan area , including three of the state 's four largest incorporated cities . Nevada 's capital is Carson City . Nevada is officially known as the Silver State because of the importance of silver to its history and economy . It is also known as the Battle Born State because it achieved statehood during the Civil War ( the words Battle Born also appear on the state flag ) ; as the Sagebrush State , for the native plant of the same name ; and as the Sage-hen State . Nevada is largely desert and semi-arid , much of it within the Great Basin . Areas south of the Great Basin are within the Mojave Desert , while Lake Tahoe and the Sierra Nevada lie on the western edge . About 86% of the state 's land is managed by various jurisdictions of the U.S. federal government , both civilian and military . Before European contact , American Indians of the Paiute , Shoshone , and Washoe tribes inhabited the land that is now Nevada . The first Europeans to explore the region were Spanish .
The Bow City crater is a potential meteorite impact crater located in southern Alberta , Canada . The 8-kilometre-wide ( 5.0 mi ) crater was discovered in 2012 by Wei Xie of the University of Alberta . The crater is estimated to have formed approximately 70 million years ago . The crater is not directly visible from the surface , as it is buried under approximately a kilometer of overburden . Petrochemical seismic studies provided the first clues to the existence of the crater .
Alberta is a province of Canada . With an estimated population of 4,067,175 as of 2016 census , it is Canada 's fourth most populous province and the most populous of Canada 's three prairie provinces . Its area is about 660,000 square kilometres ( 250,000 sq mi ) . Alberta and its neighbour Saskatchewan were districts of the Northwest Territories until they were established as provinces on September 1 , 1905 . The premier is Jason Kenney as of April 30 , 2019 . Alberta is bordered by the provinces of British Columbia to the west and Saskatchewan to the east , the Northwest Territories to the north , and the U.S. state of Montana to the south . Alberta is one of three Canadian provinces and territories to border only a single U.S. state and one of only two landlocked provinces . It has a predominantly humid continental climate , with stark contrasts over a year ; but seasonal temperature average swings are smaller than in areas further east , due to winters being warmed by occasional chinook winds bringing sudden warming . Alberta 's capital , Edmonton , is near the geographic centre of the province and is the primary supply and service hub for Canada 's crude oil , the Athabasca oil sands and other northern resource industries . About 290 km ( 180 mi ) south of the capital is Calgary , the largest city in Alberta . Calgary and Edmonton centre Alberta 's two census metropolitan areas , both of which have populations exceeding one million , while the province has 16 census agglomerations . Tourist destinations in the province include Banff , Canmore , Drumheller , Jasper , Sylvan Lake and Lake Louise .
The Corossol structure , which is also known as the Corossol crater , is a circular , 4.3-by-3.9-kilometer ( 2.7 by 2.4 mi ) in diameter , underwater bedrock feature that is exposed on the gulf floor of the northwestern Gulf of Saint Lawrence 20-kilometer ( 12 mi ) offshore of the city of Sept-Îles , Quebec in eastern Canada . It is hypothesized to be a possible pre-Pleistocene , extraterrestrial impact structure . It lies underwater at a depth of 40-208-meter ( 131-682 ft ) . This underwater feature was found during the study of high-resolution bathymetric and sub-bottom profiler data collected south of the city of Sept-Iles in the northwestern Gulf of Saint Lawrence .
Quebec ( /k ( w ) ɪˈbɛk/ ( listen ) ; French : Québec [ kebɛk ] ( listen ) ) is one of the thirteen provinces and territories of Canada . It is bordered to the west by the province of Ontario and the bodies of water James Bay and Hudson Bay ; to the north by Hudson Strait and Ungava Bay ; to the east by the Gulf of Saint Lawrence and the province of Newfoundland and Labrador ; and to the south by the province of New Brunswick and the U.S. states of Maine , New Hampshire , Vermont , and New York . It also shares maritime borders with Nunavut , Prince Edward Island , and Nova Scotia . Quebec is Canada 's largest province by area and its second-largest administrative division ; only the territory of Nunavut is larger . It is historically and politically considered to be part of Central Canada ( with Ontario ) . Quebec is the second-most populous province of Canada , after Ontario . It is the only one to have a predominantly French-speaking population , with French as the sole provincial official language . Most inhabitants live in urban areas near the Saint Lawrence River between Montreal and Quebec City , the capital . Approximately half of Quebec residents live in the Greater Montreal Area , including the Island of Montreal . English-speaking communities and English-language institutions are concentrated in the west of the island of Montreal but are also significantly present in the Outaouais , Eastern Townships , and Gaspé regions . The Nord-du-Québec region , occupying the northern half of the province , is sparsely populated and inhabited primarily by Aboriginal peoples . The climate around the major cities is four-seasons continental with cold and snowy winters combined with warm to hot humid summers , but farther north long winter seasons dominate and as a result the northern areas of the province are marked by tundra conditions .
The Decorah crater , also called the Decorah impact structure , is a possible impact crater located on the east side of the city of Decorah in Iowa , United States . It is thought to have been caused by a meteor about 200 metres ( 660 ft ) wide which struck during the Middle Ordovician Period , circa 470 million years ago .
Iowa ( /ˈaɪəwə/ ( listen ) ) is a state in the Midwestern United States , bordered by the Mississippi River to the east and the Missouri River and Big Sioux River to the west . It is bordered by six states : Wisconsin to the northeast , Illinois to the east and southeast , Missouri to the south , Nebraska to the west , South Dakota to the northwest , and Minnesota to the north . In colonial times , Iowa was a part of French Louisiana and Spanish Louisiana ; its state flag is patterned after the flag of France . After the Louisiana Purchase , people laid the foundation for an agriculture-based economy in the heart of the Corn Belt . In the latter half of the 20th century , Iowa 's agricultural economy made the transition to a diversified economy of advanced manufacturing , processing , financial services , information technology , biotechnology , and green energy production . Iowa is the 26th most extensive in land area and the 30th most populous of the 50 U.S. states . The state 's capital , most populous city , and largest metropolitan area fully located within the state is Des Moines . A portion of the larger Omaha , Nebraska , metropolitan area extends into three counties of southwest Iowa . Iowa has been listed as one of the safest states to live in .
The Gatun structure is a possible eroded impact crater . It is named after the nearby Gatun Lake in Panama . It was first discovered in 1972 by geologist Bob Stewart and later studied by Livio L. Tornabene from the University of South Florida Department of Geology . The structure is estimated to have formed about 20 million years ago , during the Miocene epoch . Despite the considerable erosion , it was possible to estimate the original diameter to have been 2.7 to 3 km , assuming the impact hypothesis is correct . Although diagnostic evidence of impact has not been reported , evidence favoring an impact origin include the recovery of possible impact glass at the site . Alternatively , the site may be of volcanic origin .
Panama ( /ˈpænəmɑː/ ( listen ) PAN-ə-mah , /pænəˈmɑː/ pan-ə-MAH ; Spanish : Panamá IPA : [ panaˈma ] ( listen ) ) , officially the Republic of Panama ( Spanish : República de Panamá ) , is a transcontinental country in Central America and South America , bordered by Costa Rica to the west , Colombia to the southeast , the Caribbean Sea to the north , and the Pacific Ocean to the south . The capital and largest city is Panama City , whose metropolitan area is home to nearly half the country 's 4 million people . Panama was inhabited by indigenous tribes before Spanish colonists arrived in the 16th century . It broke away from Spain in 1821 and joined the Republic of Gran Colombia , a union of Nueva Granada , Ecuador , and Venezuela . After Gran Colombia dissolved in 1831 , Panama and Nueva Granada eventually became the Republic of Colombia . With the backing of the United States , Panama seceded from Colombia in 1903 , allowing the construction of the Panama Canal to be completed by the US Army Corps of Engineers between 1904 and 1914 . The 1977 Torrijos-Carter Treaties led to the transfer of the Canal from the United States to Panama on December 31 , 1999 . Revenue from canal tolls continues to represent a significant portion of Panama 's GDP , although commerce , banking , and tourism are major and growing sectors . It is regarded as a high-income country . In 2018 Panama ranked 66th in the world in terms of the Human Development Index . In 2018 , Panama was ranked seventh-most competitive economy in Latin America , according to the World Economic Forum 's Global Competitiveness Index . Covering around 40 percent of its land area , Panama 's jungles are home to an abundance of tropical plants and animals - some of them found nowhere else on earth .
Pantasma is a region in the north of Nicaragua . In the Miskito language the word Pantasma means small humans or flat head . The Spanish word Fantasma ( Galego : Pantasma ) origins from the Greek Phantasma and means ghost . The Valle de Pantasma , also called the Crater of Pantasma , is a circular valley over 12 km in diameter situated in Nicaragua . It is passed by the Rio Pantasma , a tributary of the Rio Coco ( also called Rio Segovia ) . In its center lies the village of Las Praderas , the principal place of the community of Santa Maria de Pantasma with about 40,000 inhabitants in the province of Jinotega . In the poor , but fertile and agricultural intensely used valley corn , grain , fruit , and coffee are cultivated and cattle is bred . The town is the site of one of the most famous actions of the civil war between the Sandinista government and the rebel Contras . On October 18 , 1983 , the Nicaraguan Democratic Force 's Task Force Diriangén , under Comandante Mike Lima , launched a surprise attack on the town , overrunning a battalion headquarters , detonating a munitions depot , robbing a state bank , and destroying a police station , a school , and all other government offices and facilities , leaving 47 defenders and residents dead . Though a military success , politically the Sandinistas depicted the assault as a massacre and a symbol of rebel atrocities .
Nicaragua ( /ˌnɪkəˈrɑːɡwə , -ˈræɡ- , -ɡjuə/ ( listen ) ; Spanish : [ nikaˈɾaɣwa ] ( listen ) ) , officially the Republic of Nicaragua ( Spanish : República de Nicaragua ( help·info ) ) , is the largest country in the Central American isthmus , bordered by Honduras to the northwest , the Caribbean to the east , Costa Rica to the south , and the Pacific Ocean to the southwest . Managua is the country 's capital and largest city and is also the third-largest city in Central America , behind Tegucigalpa and Guatemala City . The multi-ethnic population of six million includes people of indigenous , European , African , and Asian heritage . The main language is Spanish . Indigenous tribes on the Mosquito Coast speak their own languages and English . Originally inhabited by various indigenous cultures since ancient times , the region was conquered by the Spanish Empire in the 16th century . Nicaragua gained independence from Spain in 1821 . The Mosquito Coast followed a different historical path , being colonized by the English in the 17th century and later coming under British rule . It became an autonomous territory of Nicaragua in 1860 and its northernmost part was transferred to Honduras in 1960 . Since its independence , Nicaragua has undergone periods of political unrest , dictatorship , occupation and fiscal crisis , including the Nicaraguan Revolution of the 1960s and 1970s and the Contra War of the 1980s . The mixture of cultural traditions has generated substantial diversity in folklore , cuisine , music , and literature , particularly the latter , given the literary contributions of Nicaraguan poets and writers such as Rubén Darío . Known as the land of lakes and volcanoes , Nicaragua is also home to the second-largest rainforest of the Americas .
Jeptha Knob is the highest point in the Bluegrass region of Kentucky . It is located on private property in Shelby County , Kentucky , about eight miles east of Shelbyville near the hamlet of Clay Village and rises some 300 ft ( 90 m ) higher than the surrounding rolling farmland .
Kentucky ( UK : /kɛnˈtʌki/ ken-TUK-ee , US : /kən-/ ( listen ) kən- ) , officially the Commonwealth of Kentucky , is a state located in the Southern United States . Although styled as the State of Kentucky in the law creating it , ( because in Kentucky 's first constitution , the term state was used ) , Kentucky is one of four U.S. states constituted as a commonwealth ( the others being Virginia , Pennsylvania , and Massachusetts ) . Originally a part of Virginia , in 1792 Kentucky split from it and became the 15th state to join the Union . Kentucky is the 37th most extensive and the 26th most populous of the 50 United States . Kentucky is known as the Bluegrass State , a nickname based on the bluegrass , a species of grass found in many of its pastures . One of the major regions in Kentucky is the Bluegrass Region in central Kentucky , which houses its two largest cities , Louisville and Lexington . It is a land with diverse environments and abundant resources , including the world 's longest cave system , Mammoth Cave National Park , one of the greatest lengths of navigable waterways and streams in the contiguous United States , and the two largest man-made lakes east of the Mississippi River . Kentucky is also known for horse racing , bourbon , moonshine , coal , My Old Kentucky Home historic state park , automobile manufacturing , tobacco , bluegrass music , college basketball , Kentucky Fried Chicken , and the Kentucky colonel .
Panther Mountain is one of the Catskill High Peaks , located in the Town of Shandaken in Ulster County , New York . At approximately 3,720 feet ( 1,130 m ) in elevation , it is the 18th highest in the range . A combination of factors has led geologists to believe the mountain is on the site of an ancient meteorite impact crater . Its proximity to Slide Mountain , the highest Catskill peak , the relatively short distance required to climb the mountain from the south and the excellent views available from the mountain and nearby Giant Ledge have made Panther one of the most popular hikes in the range . Aspiring members of the Catskill Mountain 3500 Club must climb it twice , at least once during winter .
New York is a state located in the Northeastern United States . New York was one of the original thirteen colonies that formed the United States . With an estimated 19.45 million residents in 2019 , it is the fourth most populous state . In order to distinguish the state from its city with the same name , it is commonly referred to as New York State ( NYS ) . The state 's most populous city , New York City , makes up over 40% of the state 's population . Two-thirds of the state 's population lives in the New York metropolitan area , and nearly 40% lives on Long Island . The state and city were both named for the 17th-century Duke of York , the future King James II of England . With an estimated population of 8.39 million in 2018 , New York City is the most populous city in the United States and the premier gateway for legal immigration to the United States . The New York metropolitan area is one of the most populous in the world . New York City is a global city , home to the United Nations Headquarters , and has been described as the cultural , financial , and media capital of the world , as well as the world 's most economically powerful city . The next four most populous cities in the state are Buffalo , Rochester , Yonkers , and Syracuse , while the state capital is Albany . The 27th largest U.S. state in land area , New York has a diverse geography .
The Johnsonville crater or the Snow 's Island crater is a circular geophysical feature that has been interpreted by some scientists as an impact crater , situated at the junction of Lynches River and the Pee Dee River in South Carolina . Snow 's Island , at that point , is believed to be the upthrust of the center after the impact . This eight-mile-wide crater is not well defined at the surface and was discovered by magnetic anomalies and supported by the study of well drilling cores . Supposed impact breccia was found in these cores . The Russian Academy of Sciences lists the structure as a proven impact crater , however the Earth Impact Database ( EID ) does not list it as confirmed .
South Carolina ( /ˌkærəˈlaɪnə/ ( listen ) ) is a state in the Southeastern United States and the easternmost of the Deep South . It is bordered to the north by North Carolina , to the southeast by the Atlantic Ocean , and to the southwest by Georgia across the Savannah River . South Carolina became the eighth state to ratify the U.S. Constitution on May 23 , 1788 . It also became the first state to vote in favor of secession from the Union on December 20 , 1860 . After the American Civil War , it was readmitted into the United States on June 25 , 1868 . South Carolina is the 40th most extensive and 23rd most populous U.S. state . Its GDP as of 2013 was $ 183.6 billion , with an annual growth rate of 3.13% . South Carolina is composed of 46 counties . The capital is Columbia with a population of 133,451 in 2018 ; while its largest city is Charleston with a 2018 population of 136,208 . The Greenville-Anderson-Mauldin metropolitan area is the largest in the state , with a 2018 population estimate of 906,626 . South Carolina is named in honor of King Charles I of England , who first formed the English colony , with Carolus being Latin for Charles .
The Toms Canyon impact crater is a probable impact crater where one or more asteroids struck the Atlantic continental shelf , about 100 miles ( 160 km ) east of Atlantic City , New Jersey . The submarine canyon is the drowned glacial-age mouth of Toms River . The crater dates to the late Eocene geological time period ( about 35 million years ago ) , and may have been formed by the same event as the larger Chesapeake Bay impact crater ( and possibly the Popigai crater in Siberia ) , 200 miles ( 320 km ) to the southwest at the mouth of Chesapeake Bay , also dating to the late Eocene . Seismic reflection profiles , studied by USGS scientists , show that the crater was formed by an object or objects which struck from the southwest at a glancing angle and formed a long , oval crater . Since impact , sediment filled part of the crater , giving it its present triangular shape .
New Jersey is a state in the Mid-Atlantic region of the Northeastern United States . It is bordered on the north and east by the state of New York ; on the east , southeast , and south by the Atlantic Ocean ; on the west by the Delaware River and Pennsylvania ; and on the southwest by the Delaware Bay and the State of Delaware . New Jersey is the fourth-smallest state by area but the 11th-most populous , with 9 million residents as of 2017 and an area of 8,722.58 square miles , making it the most densely populated of the 50 U.S. states , with its biggest city being Newark . New Jersey lies completely within the combined statistical areas of New York City and Philadelphia . New Jersey was the second-wealthiest U.S. state by median household income as of 2017 . New Jersey was inhabited by Native Americans for more than 2,800 years , with historical tribes such as the Lenape along the coast . In the early 17th century , the Dutch and the Swedes founded the first European settlements in the state . The English later seized control of the region , naming it the Province of New Jersey after the largest of the Channel Islands , Jersey , and granting it as a colony to Sir George Carteret and John Berkeley , 1st Baron Berkeley of Stratton . New Jersey was the site of several important battles during the American Revolutionary War in the 18th century . In the 19th century , factories in the cities Camden , Paterson , Newark , Trenton , Jersey City , and Elizabeth ( known as the Big Six ) , helped drive the Industrial Revolution . New Jersey 's geographic location at the center of the Northeast megalopolis , between Boston and New York City to the northeast , and Philadelphia , Baltimore , and Washington , D.C. , to the southwest , fueled its rapid growth through the process of suburbanization in the second half of the 20th century . At the turn of the 21st century , this suburbanization began reverting with the consolidation of New Jersey 's culturally diverse populace toward more urban settings within the state , with towns home to commuter rail stations outpacing the population growth of more automobile-oriented suburbs since 2008 .
The Victoria Island structure is a 5.5 km ( 3 mi ) bowl-shaped structure buried in the shale sediments of the Sacramento-San Joaquin River Delta , 12 miles ( 19 km ) west of Stockton , California . The circular structure is part of a former sea bed , and lies 1,490-1,600 meters ( 4,890-4,250 ft ) below sea level . Discovered during oil exploration and reported at the Lunar and Planetary Science Conference in Houston , Texas , in March 2007 , it is thought to be a buried impact crater formed between 37 and 49 million years ago . Victoria Island , which the structure is named for , is in the San Joaquin River Delta at approximately 37°53′24″N 121°32′06″W / 37.890°N 121.535°W / 37.890 ; -121.535 . The current publications do not list a more precise location for the impact structure than the island .
California is a state in the Pacific Region of the United States . With 39.5 million residents across a total area of about 163,696 square miles ( 423,970 km2 ) , California is the most populous U.S. state and the third-largest by area . The state capital is Sacramento . The Greater Los Angeles Area and the San Francisco Bay Area are the nation 's second- and fifth-most populous urban regions , with 18.7 million and 9.7 million residents respectively . Los Angeles is California 's most populous city , and the country 's second-most populous , after New York City . California also has the nation 's most populous county , Los Angeles County , and its largest county by area , San Bernardino County . The City and County of San Francisco is both the country 's second most densely populated major city after New York City and the fifth most densely populated county , behind only four of the five New York City boroughs . California 's economy , with a gross state product of $ 3.0 trillion , is the largest sub-national economy in the world . If it were a country , California would be the fifth-largest economy in the world ( larger than the United Kingdom , France , or India ) , and the 36th-most populous as of 2017 [ update ] . The Greater Los Angeles Area and the San Francisco Bay Area are the nation 's second- and third-largest urban economies ( $ 1.3 trillion and $ 1.0 trillion respectively as of 2018 [ update ] ) , after the New York metropolitan area . The San Francisco Bay Area PSA had the nation 's highest gross domestic product per capita in 2018 ( $ 106,757 ) among large primary statistical areas , and is home to three of the world 's ten largest companies by market capitalization and three of the world 's ten richest people . California culture is considered a global trendsetter in popular culture , communication , information , innovation , environmentalism , economics , politics , and entertainment .
The Weaubleau structure is a probable meteorite impact site in western Missouri near the towns of Gerster , Iconium , Osceola , and Vista . It is believed to have been caused by a 1,200 feet ( 370 m ) meteoroid between 335 and 340 million years ago during the middle Mississippian Period ( Latest Osagean to Earliest Meramecian ) . It is listed by the Impact Field Studies Group as a probable impact structure . The structure consists of an area of severe structural deformation and extensive brecciation that was poorly understood and had been thought to be the result of either thrusting over a dome or a cryptoexplosive event . A 12 mi ( 19 km ) circular structure was discovered by geologist Kevin R. Evans through examination of digital elevation data . The structure was originally called the Weaubleau-Osceola structure after Weaubleau Creek and Osceola . It is now known as the Weaubleau structure . Because the site was covered by later Pennsylvanian Period sediments , and only partially exposed to erosion relatively recently , its structure is well preserved , and its age can be determined with fair accuracy . It is one of a series of known or suspected impact sites along the 38th parallel in the states of Illinois , Missouri , and Kansas . These 38th parallel structures are thought to possibly be the result of a serial impact , similar to that of comet Shoemaker-Levy 9 on Jupiter , an extremely unlikely event on Earth . The argument for a serial strike would be greatly strengthened if the ages of the other 38th parallel structures could be constrained to the same period as the Weaubleau structure . The Weaubleau structure is one of the fifty largest known impact craters on earth and the fourth largest in the United States .
Missouri is a state in the Midwestern United States . With over six million residents , it is the 18th-most populous state of the Union . The largest urban areas are St. Louis , Kansas City , Springfield and Columbia ; the capital is Jefferson City . The state is the 21st-most extensive in area . Missouri is bordered by eight states ( tied for the most with Tennessee ) : Iowa to the north , Illinois , Kentucky and Tennessee ( via the Mississippi River ) to the east , Arkansas to the south and Oklahoma , Kansas and Nebraska to the west . In the south are the Ozarks , a forested highland , providing timber , minerals and recreation . The Missouri River , after which the state is named , flows through the center of the state into the Mississippi River , which makes up Missouri 's eastern border . Humans have inhabited the land now known as Missouri for at least 12,000 years . The Mississippian culture built cities and mounds , before declining in the 14th century . When European explorers arrived in the 17th century , they encountered the Osage and Missouria nations . The French established Louisiana , a part of New France , founding Ste . Genevieve in 1735 and St. Louis in 1764 .
St. Helena Parish ( French : Paroisse de Sainte-Hélène ) is a parish in the U.S. state of Louisiana . As of the 2010 census , the population was 11,203 . Its seat is Greensburg . The parish was created in 1810 . St. Helena Parish is part of the Baton Rouge , LA Metropolitan Statistical Area .
Louisiana ( /luˌiːziˈænə/ ( listen ) , /ˌluːzi-/ ( listen ) ) [ a ] is a state in the Deep South region of the South Central United States . It is the 31st most extensive and the 25th most populous of the 50 United States . Louisiana is bordered by the state of Texas to the west , Arkansas to the north , Mississippi to the east , and the Gulf of Mexico to the south . A large part of its eastern boundary is demarcated by the Mississippi River . Louisiana is the only U.S. state with political subdivisions termed parishes , which are equivalent to counties . The state 's capital is Baton Rouge , and its largest city is New Orleans . Much of the state 's lands were formed from sediment washed down the Mississippi River , leaving enormous deltas and vast areas of coastal marsh and swamp . [ self-published source ] These contain a rich southern biota ; typical examples include birds such as ibis and egrets . There are also many species of tree frogs , and fish such as sturgeon and paddlefish . In more elevated areas , fire is a natural process in the landscape and has produced extensive areas of longleaf pine forest and wet savannas . These support an exceptionally large number of plant species , including many species of terrestrial orchids and carnivorous plants . Louisiana has more Native American tribes than any other southern state , including four that are federally recognized , ten that are state recognized , and four that have not received recognition .