The Eastern Continental Divide, Eastern Divide or Appalachian Divide is a hydrological divide in eastern North America that separates the easterly Atlantic Seaboard watershed from the westerly Gulf of Mexico watershed. It is one of six continental hydrological divides of North America which define several drainage basins, each of which drains to a particular body of water.
The divide nearly spans the United States from south of Lake Ontario through the Florida peninsula, and consists of raised terrain including the Appalachian Mountains to the north, the southern Piedmont Plateau and lowland ridges in the Atlantic Coastal Plain to the south.
The divide's northern portion winds through the middle of the Appalachian Mountains, either through the interior of the Allegheny Plateau or along the Allegheny Mountains. In this portion, the western drainage of the divide flows into the watersheds of the Allegheny River, Monongahela River, and New River, all tributaries of the Ohio River. The eastern drainage flows into the watersheds of the Susquehanna River, Potomac River, and James River, all of which flow into Chesapeake Bay before entering the Atlantic Ocean.
At its northern terminus, the Eastern Continental Divide originates at Triple Divide Peak [a] in Ulysses Township, Pennsylvania, about 10 mi (16 km) south of the New York-Pennsylvania border, where it diverges from the St. Lawrence Divide. This point divides the eastern United States into three watersheds: those of the Genesee River flowing into Lake Ontario and then the St. Lawrence River to the north; Pine Creek into the Susquehanna River as part of the Atlantic seaboard watershed to the east; and the Allegheny River into the Ohio, the Mississippi, and the Gulf of Mexico to the west.
From north to south, the divide passes through the broader Allegheny Plateau region, following the boundary between the Allegheny River and Susquehanna River watersheds through most of Pennsylvania. At Blue Knob near Altoona, the Divide begins to follow Allegheny Mountain and then Little Savage Mountain. A few miles before the state border, the Divide begins to separate the Youghiogheny River and Potomac River watersheds. [2]
In Maryland, the Divide runs significantly west of the Allegheny Front, following Backbone Mountain, and passing near the source of the North Branch Potomac River at the Fairfax Stone. The Divide then passes through a plateau of the Allegheny Mountains of West Virginia, passing between the north end of the Canaan Valley in the Cheat River watershed, and the Mount Storm Lake basin in the Potomac River watershed. The Divide then rejoins the Allegheny Front.
A significant portion of the Divide forms part of the border between West Virginia and Virginia along Allegheny Mountain and then Peters Mountain, separating the Greenbrier River and James River watersheds. It then makes a dramatic arc to the east around the Sinking Creek valley, and then follows the hill crest east of Blacksburg, Virginia. [3] [4]
The divide's central portion generally follows the easternmost ridge of the Blue Ridge Mountains and thus of the Appalachian Mountains as a whole, which takes the form of a high escarpment. In this portion, the western drainage of the divide flows into the watersheds of the New River and Tennessee River, both tributaries of the Ohio River. The eastern drainage flows into the watersheds of the Roanoke River, Pee Dee River, and Santee River.
The divide initially separates the headwaters of the New River from that of the Roanoke River. [3] [4] Just before the Divide passes into North Carolina, it begins to separate the New River and Yadkin River watersheds. It then separates upper tributaries of the Tennessee River from those of the Santee River. [5] Its high point is on Grandfather Mountain at 5,946 feet (1,812 m); although Mount Mitchell is the highest point in the Appalachian Mountains, it is not on the Divide, but 4 miles west of it.
Past the southern end of the Appalachian Mountains, the divide's southern portion winds through the lowlands of Georgia and Florida. In this portion, the western drainage of the divide flows into the watersheds of the Apalachicola River, Suwannee River, Withlacoochee River, and Peace River, all of which drain directly to the Gulf of Mexico without reaching the Ohio River first. The eastern drainage flows into the watersheds of the Savannah River, Altamaha River, Satilla River, St. Marys River, and St. Johns River.
In Georgia, the Divide generally separates the Apalachicola River, watershed in the west from the Savannah River and Altamaha River watersheds to the east, passing through the Atlanta metropolitan area and extending past the southern end of the Appalachian Mountains southeasterly across the Georgia plateau. In southern Georgia, it separates the Suwannee River and Satilla River watersheds. [6]
In Florida, the Divide generally follows the western edge of the St. Marys River and then St. Johns River, meandering into the low country of Northern Florida until it reaches Central Florida. The west side of the divide continues to be the Suwannee River and then the Withlacoochee River watersheds.
The southern terminus of the Eastern Continental Divide is at the triple divide between the St. Johns, Peace, and Kissimmee River watersheds, which is in Haines City, Florida on the Lake Wales Ridge. [7] [8] [9] [10] Because the Kissimmee River flows into Lake Okeechobee, whose distributaries reach both the Gulf of Mexico and the Atlantic Ocean via low swampland covered by a network of diverging canals and natural waterways, its watershed's land is not clearly divisible between the two watersheds.[ citation needed ]
Because the divide is at or in proximity to the highest terrain, air is forced upwards regardless of wind direction. This process of orographic enhancement leads to higher precipitation than surrounding areas. In winter, the divide is often much snowier than surrounding areas, due to orographic enhancement and cooler temperatures with elevation.
Prior to about 1760, north of Spanish Florida, the Appalachian Divide represented the boundary between British and French colonial possessions in North America. [11] The Royal Proclamation of 1763 separated settled lands of the Thirteen Colonies from lands north and west of it designated the Indian Reserve; the proclamation border ran along the Appalachian Divide but extended beyond its Pennsylvania-New York terminus north into New England.
The exact route of the ECD shifts over time due to erosion, tectonic activity, construction projects, and other factors.
The Appalachian Mountains, often called the Appalachians, are a mountain range in eastern to northeastern North America. The term "Appalachian" refers to several different regions associated with the mountain range, and its surrounding terrain. The general definition used is one followed by the United States Geological Survey and the Geological Survey of Canada to describe the respective countries' physiographic regions. The U.S. uses the term Appalachian Highlands and Canada uses the term Appalachian Uplands; the Appalachian Mountains are not synonymous with the Appalachian Plateau, which is one of the provinces of the Appalachian Highlands.
The Atlantic seaboard watershed is a watershed of the Atlantic Ocean in eastern North America along the Atlantic Canada (Maritimes) coast south of the Gulf of Saint Lawrence Watershed, and the East Coast of the United States north of the Kissimmee River watershed of Lake Okeechobee basin in the central Florida Peninsula.
The Allegheny Mountain Range — also spelled Alleghany or Allegany, less formally the Alleghenies — is part of the vast Appalachian Mountain Range of the Eastern United States and Canada. Historically it represented a significant barrier to westward land travel and development. The Alleghenies have a northeast–southwest orientation, running for about 300 miles (480 km) from north-central Pennsylvania southward, through western Maryland and eastern West Virginia.
The Allegheny Plateau is a large dissected plateau area of the Appalachian Mountains in western and central New York, northern and western Pennsylvania, northern and western West Virginia, and eastern Ohio. It is divided into the unglaciated Allegheny Plateau and the glaciated Allegheny Plateau.
The Little Conemaugh River is a tributary of the Conemaugh River, approximately 30 miles (48 km) long, in western Pennsylvania in the United States.
Backbone Mountain is a ridge of the Allegheny Mountains of the central Appalachian Mountain Range. It is situated in the U.S. states of West Virginia and Maryland and forms a portion of the Eastern Continental Divide. Within the state of Maryland, Backbone Mountain reaches an elevation of 3,360 feet or 1,024 metres, making it Maryland's highest point.
The Allegheny Front is the major southeast- or east-facing escarpment in the Allegheny Mountains in southern Pennsylvania, western Maryland, eastern West Virginia, and western Virginia. The Allegheny Front forms the boundary between the Ridge-and-Valley Appalachians to its east and the Appalachian Plateau to its west. The Front is closely associated with the Appalachian Mountains' Eastern Continental Divide, which in this area divides the waters of the Ohio/Mississippi river system, flowing to the Gulf of Mexico, from rivers flowing into Chesapeake Bay and from there into the Atlantic Ocean.
A drainage divide, water divide, ridgeline, watershed, water parting or height of land is elevated terrain that separates neighboring drainage basins. On rugged land, the divide lies along topographical ridges, and may be in the form of a single range of hills or mountains, known as a dividing range. On flat terrain, especially where the ground is marshy, the divide may be difficult to discern.
The Potomac Highlands of West Virginia centers on five West Virginian counties in the upper Potomac River watershed in the western portion of the state's eastern panhandle, bordering Maryland and Virginia. Because of geographical proximity, similar topography and landscapes, and shared culture and history, the Potomac Highlands region is also considered to include Pocahontas, Randolph, and Tucker Counties, even though they are in the Monongahela River or New River watersheds and not the Potomac River watershed.
North America is the third largest continent, and is also a portion of the second largest supercontinent if North and South America are combined into the Americas and Africa, Europe, and Asia are considered to be part of one supercontinent called Afro-Eurasia. With an estimated population of 580 million and an area of 24,709,000 km2 (9,540,000 mi2), the northernmost of the two continents of the Western Hemisphere is bounded by the Pacific Ocean on the west; the Atlantic Ocean on the east; the Caribbean Sea on the south; and the Arctic Ocean on the north.
The geography of Pennsylvania varies from sea level marine estuary to mountainous plateau. The state is known for its natural resources, ports, and the leading role it played in the founding and history of the United States.
The Great Indian Warpath (GIW)—also known as the Great Indian War and Trading Path, or the Seneca Trail—was that part of the network of trails in eastern North America developed and used by Native Americans which ran through the Great Appalachian Valley. The system of footpaths extended from what is now upper New York to deep within Alabama. Various Native peoples traded and made war along the trails, including the Catawba, numerous Algonquian tribes, the Cherokee, and the Iroquois Confederacy. The British traders' name for the route was derived from combining its name among the northeastern Algonquian tribes, Mishimayagat or "Great Trail", with that of the Shawnee and Delaware, Athawominee or "Path where they go armed".
The Tennessee Valley Divide is the boundary of the drainage basin of the Tennessee River and its tributaries.
The geography of New York varies widely across the state. Most of New York is dominated by farms, forests, rivers, mountains, and lakes. New York's Adirondack Park is larger than any U.S. National Park in the contiguous United States. Niagara Falls, on the Niagara River as it flows from Lake Erie to Lake Ontario, is a popular attraction. The Hudson River begins near Lake Tear of the Clouds and flows south through the eastern part of the state without draining lakes George or Champlain. Lake George empties at its north end into Lake Champlain, whose northern end extends into Canada, where it drains into the Richelieu River and then the St. Lawrence. Four of New York City's five boroughs are on the three islands at the mouth of the Hudson River: Manhattan Island, Staten Island, and Brooklyn and Queens on Long Island.
A continental divide is a drainage divide on a continent such that the drainage basin on one side of the divide feeds into one ocean or sea, and the basin on the other side either feeds into a different ocean or sea, or else is endorheic, not connected to the open sea. Every continent on earth except Antarctica has at least one continental drainage divide; islands, even small ones like Killiniq Island on the Labrador Sea in Canada, may also host part of a continental divide or have their own island-spanning divide. The endpoints of a continental divide may be coastlines of gulfs, seas or oceans, the boundary of an endorheic basin, or another continental divide. One case, the Great Basin Divide, is a closed loop around an endorheic basin. The endpoints where a continental divide meets the coast are not always definite since the exact border between adjacent bodies of water is usually not clearly defined. The International Hydrographic Organization's publication Limits of Oceans and Seas defines exact boundaries of oceans, but it is not universally recognized. Where a continental divide meets an endorheic basin, such as the Great Divide Basin of Wyoming, the continental divide splits and encircles the basin. Where two divides intersect, they form a triple divide, or a tripoint, a junction where three watersheds meet.
Savage Mountain is an anticline extending from Bedford County, Pennsylvania southwest into Western Maryland. It is the western side of the Ridge-and-Valley Appalachians, and the eastern portion of the ridge forms the border of Garrett and Allegany Counties of Maryland.
The Saint Lawrence River Divide is a continental divide in central and eastern North America that separates the Great Lakes-St. Lawrence River Basin from the southerly Atlantic Ocean watersheds. Water, including rainfall and snowfall, lakes, rivers and streams, north and west of the divide, drains into the Gulf of St. Lawrence or the Labrador Sea; water south and east of the divide drains into the Atlantic Ocean or Gulf of Mexico. The divide is one of six continental divides in North America that demarcate several watersheds that flow to different gulfs, seas or oceans.
Blair Gap, one of the gaps of the Allegheny, is a water gap along the eastern face atop the Allegheny Front escarpment. Like other gaps of the Allegheny, the slopes of Blair Gap were amenable to foot travel, pack mules, and possibly wagons allowing Amerindians, and then, after about 1778–1780 settlers, to travel west into the relatively depopulated Ohio Country decades before the railroads were born and tied the country together with steel.
The gaps of the Allegheny, meaning gaps in the Allegheny Ridge in west-central Pennsylvania, is a series of escarpment eroding water gaps along the saddle between two higher barrier ridge-lines in the eastern face atop the Allegheny Ridge or Allegheny Front escarpment. The front extends south through Western Maryland and forms much of the border between Virginia and West Virginia, in part explaining the difference in cultures between those two post-Civil War states. While not totally impenetrable to daring and energetic travelers on foot, passing the front outside of the water gaps with even sure footed mules was nearly impossible without navigating terrain where climbing was necessary on slopes even burros would find extremely difficult.