The
Allegheny Plateau is a large
dissected plateauA dissected plateau is a plateau area that has been uplifted, then severely eroded so that the relief is sharp. Such an area may be referred to as mountainous, but dissected plateaus are distinguishable from orogenic mountain belts by the lack of folding, metamorphism, extensive faulting, or...
area in western and central
New YorkNew York is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous. The state is bordered by New Jersey and Pennsylvania to the south, and Connecticut, Massachusetts and Vermont to the east...
, northern and western
PennsylvaniaThe Commonwealth of Pennsylvania , often colloquially referred to as PA by natives and Northeasterners, is a state located in the Northeastern and Middle Atlantic regions of the United States...
, northern
West VirginiaWest Virginia is a state in the Appalachian and Mid-Atlantic regions of the United States, bordered by Virginia to the southeast, Kentucky to the southwest, Ohio to the northwest, and Pennsylvania and Maryland to the northeast...
, and eastern
OhioOhio is a Midwestern state of the United States. The thirty-fourth largest state by area in the U.S., it is the seventh-most populous with nearly 11.5 million residents...
. It is divided into the
unglaciated Allegheny PlateauThe Unglaciated Allegheny Plateau is located in an arc around southeastern Ohio into western Pennsylvania and West Virginia. This area is a dissected plateau, characterized by sandstone, shale, and many coal seams...
and the
glaciated Allegheny PlateauThe Glaciated Allegheny Plateau is that portion of the Allegheny Plateau that lies within the area covered by the last glaciation. As a result, this area of the Allegheny Plateau has lower relief and more gentle slopes than the relatively rugged Unglaciated Allegheny Plateau...
.
The plateau extends southward into western
West VirginiaWest Virginia is a state in the Appalachian and Mid-Atlantic regions of the United States, bordered by Virginia to the southeast, Kentucky to the southwest, Ohio to the northwest, and Pennsylvania and Maryland to the northeast...
, eastern
KentuckyThe Commonwealth of Kentucky is a state located in the East Central United States of America. Kentucky is a Southern state situated in the Upland South, although the state is infrequently placed, geographically and culturally, in the Midwest. Kentucky is one of four U.S. states constituted as a...
and
TennesseeTennessee is a state located in the Southeastern United States. According to the 2008 census, it has a population of 6,214,888, an increase of nearly 9.5% since 2000. Tennessee is the 14th fastest growing state in the US and is ranked 17th by population. It is ranked 36th by total land area. In...
where it is instead called the
Cumberland PlateauThe Cumberland Plateau is the southern part of the Appalachian Plateau. It includes much of eastern Kentucky and western West Virginia, part of Tennessee, and a small portion of northern Alabama and northwest Georgia
. The terms "Allegheny Plateau" and the "Cumberland Plateau" both refer...
.
The plateau terminates in the east at the
Allegheny MountainsThe Allegheny Mountain Range — informally, the Alleghenies — is part of the vast Appalachian Mountain Range of the eastern United States and Canada...
, which are the highest ridges just west of the
Allegheny FrontThe Allegheny Front is a portion of the escarpment that delineates the eastern edge of the Appalachian Plateau and the higher ranges of the Allegheny Mountains, separating them from the lower Alleghenies to the east...
. The front extends from central Pennsylvania into eastern West Virginia.
The plateau is bordered on the west by glacial till plains in the north, generally north of the
Ohio RiverThe Ohio River is the largest tributary, by volume, of the Mississippi River. It is approximately 981 miles long and is located in the eastern United States....
, and the
Bluegrass regionThe Bluegrass Region is a region in the United States, mostly in northern Kentucky, containing a majority of the state's population. The region is centered on , and includes and , as it extends into southwestern Ohio and southeastern Indiana...
in the south, generally south of the Ohio River.
Elevations vary greatly.
The
Allegheny Plateau is a large
dissected plateauA dissected plateau is a plateau area that has been uplifted, then severely eroded so that the relief is sharp. Such an area may be referred to as mountainous, but dissected plateaus are distinguishable from orogenic mountain belts by the lack of folding, metamorphism, extensive faulting, or...
area in western and central
New YorkNew York is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous. The state is bordered by New Jersey and Pennsylvania to the south, and Connecticut, Massachusetts and Vermont to the east...
, northern and western
PennsylvaniaThe Commonwealth of Pennsylvania , often colloquially referred to as PA by natives and Northeasterners, is a state located in the Northeastern and Middle Atlantic regions of the United States...
, northern
West VirginiaWest Virginia is a state in the Appalachian and Mid-Atlantic regions of the United States, bordered by Virginia to the southeast, Kentucky to the southwest, Ohio to the northwest, and Pennsylvania and Maryland to the northeast...
, and eastern
OhioOhio is a Midwestern state of the United States. The thirty-fourth largest state by area in the U.S., it is the seventh-most populous with nearly 11.5 million residents...
. It is divided into the
unglaciated Allegheny PlateauThe Unglaciated Allegheny Plateau is located in an arc around southeastern Ohio into western Pennsylvania and West Virginia. This area is a dissected plateau, characterized by sandstone, shale, and many coal seams...
and the
glaciated Allegheny PlateauThe Glaciated Allegheny Plateau is that portion of the Allegheny Plateau that lies within the area covered by the last glaciation. As a result, this area of the Allegheny Plateau has lower relief and more gentle slopes than the relatively rugged Unglaciated Allegheny Plateau...
.
The plateau extends southward into western
West VirginiaWest Virginia is a state in the Appalachian and Mid-Atlantic regions of the United States, bordered by Virginia to the southeast, Kentucky to the southwest, Ohio to the northwest, and Pennsylvania and Maryland to the northeast...
, eastern
KentuckyThe Commonwealth of Kentucky is a state located in the East Central United States of America. Kentucky is a Southern state situated in the Upland South, although the state is infrequently placed, geographically and culturally, in the Midwest. Kentucky is one of four U.S. states constituted as a...
and
TennesseeTennessee is a state located in the Southeastern United States. According to the 2008 census, it has a population of 6,214,888, an increase of nearly 9.5% since 2000. Tennessee is the 14th fastest growing state in the US and is ranked 17th by population. It is ranked 36th by total land area. In...
where it is instead called the
Cumberland PlateauThe Cumberland Plateau is the southern part of the Appalachian Plateau. It includes much of eastern Kentucky and western West Virginia, part of Tennessee, and a small portion of northern Alabama and northwest Georgia
. The terms "Allegheny Plateau" and the "Cumberland Plateau" both refer...
.
The plateau terminates in the east at the
Allegheny MountainsThe Allegheny Mountain Range — informally, the Alleghenies — is part of the vast Appalachian Mountain Range of the eastern United States and Canada...
, which are the highest ridges just west of the
Allegheny FrontThe Allegheny Front is a portion of the escarpment that delineates the eastern edge of the Appalachian Plateau and the higher ranges of the Allegheny Mountains, separating them from the lower Alleghenies to the east...
. The front extends from central Pennsylvania into eastern West Virginia.
The plateau is bordered on the west by glacial till plains in the north, generally north of the
Ohio RiverThe Ohio River is the largest tributary, by volume, of the Mississippi River. It is approximately 981 miles long and is located in the eastern United States....
, and the
Bluegrass regionThe Bluegrass Region is a region in the United States, mostly in northern Kentucky, containing a majority of the state's population. The region is centered on , and includes and , as it extends into southwestern Ohio and southeastern Indiana...
in the south, generally south of the Ohio River.
Elevations vary greatly. In the glaciated Allegheny Plateau, relief may only reach one hundred feet or less. In the unglaciated Allegheny Plateau in southeastern Ohio and westernmost West Virginia, relief is typically in the range of two hundred to four hundred feet. Absolute highest elevations in this area are often in the range of . By the Allegheny Front, however, elevations may reach well over , with relief of up to .
One of the more notable geologic areas within the Allegheny Plateau is the Hocking Hills region of southeast
OhioOhio is a Midwestern state of the United States. The thirty-fourth largest state by area in the U.S., it is the seventh-most populous with nearly 11.5 million residents...
.
Geology and physiography
The Allegheny Plateau is a
physiographic sectionThe physiographic regions of the world are a means of defining the Earth's landforms into distinct regions based upon Nevin Fenneman's classic three-tiered approach of divisions, provinces and sections, in 1916, which although they date from the mid 1910s, are still considered basically valid, and...
of the larger
Appalachian PlateauThe Appalachian Plateau is the western part of the Appalachian mountains, stretching from New York to Georgia and Alabama. The plateau is a second level United States physiographic region....
province, which in turn is part of the larger
AppalachianThe Appalachian Mountains , often called the Appalachians, are a vast system of mountains in eastern North America. Definitions vary on the precise boundaries of the Appalachians...
physiographic division.
External links