River mile

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Part of Fourteen Mile Island in the Allegheny River - the island is named for its distance from the river's mouth in river miles. Allegheny Islands State Park, C.W. Bill Young Lock and Dam.jpg
Part of Fourteen Mile Island in the Allegheny River - the island is named for its distance from the river's mouth in river miles.

In the United States, a river mile is a measure of distance in miles along a river from its mouth. River mile numbers begin at zero and increase further upstream. The corresponding metric unit using kilometers is the river kilometer. They are analogous to vehicle roadway mile markers, except that river miles are rarely marked on the physical river; instead they are marked on navigation charts, and topographic maps. Riverfront properties are sometimes partially legally described by their river mile.


The river mile is not the same as the length of the river, rather it is a means of locating any feature along the river relative to its distance from the mouth, when measured along the course (or navigable channel) of the river. [1]

River mile zero may not be exactly at the mouth. For example, the Willamette River (which discharges into the Columbia River) has its river mile zero at the edge of the navigable channel in the Columbia, some 900 feet (270 m) beyond the mouth. [2] Also, the river mile zero for the Lower Mississippi River is located at Head of Passes, where the main stem of the Mississippi splits into three major branches before flowing into the Gulf of Mexico. Mileages are indicated as AHP (Above Head of Passes) or BHP (Below Head of Passes). [3]


River miles are used in a variety of ways. The Commonwealth of Pennsylvania, in its 2001 Pennsylvania Gazetteer of Streams, lists every named stream and every unnamed stream in a named geographic feature in the state, and gives the drainage basin area, mouth coordinates, and river mile, specifically the distance from the mouth of the tributary to the mouth of its parent stream. [1] Some islands are named for their river mile distance, for example the Allegheny River in Pennsylvania has Six Mile Island, Nine Mile Island, Twelve Mile Island, and Fourteen Mile Island. [4] [5] (The last two islands form Allegheny Islands State Park, although Fourteen Mile Island was split into two parts by a dam). [6] [7]

The state of Ohio uses the "River Mile System of Ohio", which is "a method to reference locations on streams and rivers of Ohio". [8] This work began by hand measurements on paper maps between 1972 and 1975 and has since been converted to a computer-based electronic version, which now covers the state in 787 river mile maps. Locations of facilities such as wastewater treatment plants and water quality measurement sites are referenced via river miles. Ohio uses one of two systems. The simplest is just the name of the river and the location in river miles. In cases where there is ambiguity, for example when more than one stream has the same name, it uses a series of river mile strings referring to the distance to the ocean along either the Ohio River (and Mississippi River) or through Lake Erie (and the Saint Lawrence Seaway). [8]

The U.S. Army Corps of Engineers uses river miles for its navigation maps. [5]

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Ohio River River in the midwestern United States

The Ohio River is a 981-mile (1,579 km) long river in the United States. It is located in the midwestern United States, flowing southwesterly from western Pennsylvania south of Lake Erie to its mouth on the Mississippi River at the southern tip of Illinois. It is the third largest river by discharge volume in the United States and the largest tributary by volume of the north-south flowing Mississippi River that divides the eastern from western United States. The river flows through or along the border of six states, and its drainage basin includes parts of 15 states. Through its largest tributary, the Tennessee River, the basin includes several states of the southeastern U.S. It is the source of drinking water for three million people.

Allegheny River river in western Pennsylvania and New York, United States

The Allegheny River is a 325-mile (523 km) long headwater stream of the Ohio River in western Pennsylvania and New York, United States. The Allegheny River runs from its headwaters just below the middle of Pennsylvania's northern border northwesterly into New York then in a zigzag southwesterly across the border and through Western Pennsylvania to join the Monongahela River at the Forks of the Ohio on the "Point" of Point State Park in Downtown Pittsburgh, Pennsylvania. The Allegheny River is, by volume, the main headstream of both the Ohio and Mississippi Rivers. Historically, the Allegheny was considered to be the upper Ohio River by both Native Americans and European settlers.

Monongahela River River in Pennsylvania and West Virginia, United States

The Monongahela River — often referred to locally as the Mon — is a 130-mile-long (210 km) river on the Allegheny Plateau in north-central West Virginia and southwestern Pennsylvania. The river flows from the confluence of its west and east forks in north-central West Virginia northeasterly into southwestern Pennsylvania, then northerly to Pittsburgh and its confluence with the Allegheny River to form the Ohio River. The river's entire length is navigable via a series of locks and dams.

French Creek (Allegheny River tributary) New York

French Creek is a tributary of the Allegheny River in northwestern Pennsylvania and western New York in the United States.

Point State Park United States historic place

Point State Park is a Pennsylvania state park on 36 acres (150,000 m2) in Downtown Pittsburgh, Allegheny County, Pennsylvania, USA, at the confluence of the Allegheny and Monongahela rivers, forming the Ohio River.

Shawnee State Park (Pennsylvania)

Shawnee State Park is a 3,983-acre (1,612 ha) Pennsylvania state park in Juniata and Napier Townships, Bedford County, Pennsylvania in the United States. Shawnee Lake, a 451-acre (183 ha) warm water reservoir, is at the center of the park as its main attraction. The park's main entrance is just east of Schellsburg, along U.S. Route 30 and about 10 miles (16 km) west of the county seat of Bedford. The park is also easily accessed via State Route 31 and by State Route 96.

Inland waterways of the United States

The inland waterways of the United States include more than 25,000 mi (40,000 km) of navigable waters. Much of the commercially important waterways of the United States consist of the Mississippi River System—the Mississippi River and connecting waterways.

Larrys Creek tributary of the West Branch Susquehanna River

Larrys Creek is a 22.9-mile-long (36.9 km) tributary of the West Branch Susquehanna River in Lycoming County in the U.S. state of Pennsylvania. A part of the Chesapeake Bay drainage basin, its watershed drains 89.1 square miles (231 km2) in six townships and a borough. The creek flows south from the dissected Allegheny Plateau to the Ridge-and-valley Appalachians through sandstone, limestone, and shale from the Devonian, Mississippian, and Pennsylvanian periods.

White Deer Hole Creek tributary of the West Branch Susquehanna River

White Deer Hole Creek is a 20.5-mile (33.0 km) tributary of the West Branch Susquehanna River in Clinton, Lycoming and Union counties in the U.S. state of Pennsylvania. A part of the Chesapeake Bay drainage basin, the White Deer Hole Creek watershed drains parts of ten townships. The creek flows east in a valley of the Ridge-and-valley Appalachians, through sandstone, limestone, and shale from the Ordovician, Silurian, and Devonian periods.

Ohiopyle State Park state park in Fayette County, Pennsylvania

Ohiopyle State Park is a Pennsylvania state park on 19,052 acres (7,710 ha) in Dunbar, Henry Clay and Stewart Townships, Fayette County, Pennsylvania in the United States. The focal point of the park is the more than 14 miles (23 km) of the Youghiogheny River Gorge that passes through the park. The river provides some of the best whitewater boating in the Eastern United States. Ohiopyle State Park is bisected by Pennsylvania Route 381 south of the Pennsylvania Turnpike. The park opened to the public in 1965, but was not officially dedicated until 1971.

Elk State Park

Elk State Park is a 3,192-acre (1,292 ha) Pennsylvania state park in Jones Township, Elk County and Sergeant Township, McKean County, Pennsylvania, in the United States. East Branch Clarion River Lake is a man-made lake covering 1,160 acres (470 ha) within the park. The lake and streams in the park are stocked with cold and warm water fish. There are 3,151 acres (1,275 ha) of woods open to hunting.

Allegheny Islands State Park

Allegheny Islands State Park is a 43-acre (17 ha) Pennsylvania state park in Harmar Township, Allegheny County, Pennsylvania in the United States. The undeveloped park is composed of three alluvial islands located in the middle of the Allegheny River northeast of Pittsburgh. The islands are just north of the boroughs of Oakmont and Plum, and southwest of Cheswick. Bridges for the Pennsylvania Turnpike and the Bessemer and Lake Erie Railroad Branch of the Canadian National Railway cross the Allegheny River at the middle island.

Bucktail State Park Natural Area

Bucktail State Park Natural Area is a 16,433-acre (6,650 ha) Pennsylvania state park in Cameron and Clinton Counties in Pennsylvania in the United States. The park follows Pennsylvania Route 120 for 75 miles (121 km) between Emporium and Lock Haven. Bucktail State Park Natural Area park runs along Sinnemahoning Creek and the West Branch Susquehanna River and also passes through Renovo. The park is named for the Civil War Pennsylvania Bucktails Regiment and is primarily dedicated to wildlife viewing, especially elk.

Pennsylvania Canal former canal network in Pennsylvania

Pennsylvania Canal(or sometimes Pennsylvania Canal system) refers generally to a complex system of transportation infrastructure improvements including canals, dams, locks, tow paths, aqueducts, and viaducts. The Canal and Works were constructed and assembled over several decades beginning in 1824, the year of the first enabling act and budget items. It should be understood the first use of any railway in North America was the year 1826, so the newspapers and the Pennsylvania Assembly of 1824 applied the term then to the proposed rights of way mainly for the canals of the Main Line of Public Works to be built across the southern part of Pennsylvania.

Chartiers Creek stream in western Pennsylvania

Chartiers Creek is a tributary of the Ohio River in Western Pennsylvania in the United States. The creek was named after Peter Chartier, a trapper of French and Native American parentage who established a trading post at the mouth of the creek in 1743.

Brownsville Road street in Allegheny County, Pennsylvania

Brownsville Road is a road between Pittsburgh, at Eighteenth Street and South Avenue in Allegheny County, Pennsylvania eastwards through Mount Oliver and generally highlands situated along or near the hilltops often overlooking the Monongahela River. It has had several names over its history, and was also known at the Red Stone Road and the period it was a Plank Road managed as a toll road, the Brownsville Plank Road, or the Brownsville Turnpike, or locally, as the area grew into a city, Southern Avenue.

Redstone Creek (Pennsylvania) Stream in Pennsylvania, USA

Redstone Creek is a historically important widemouthed canoe and river boat-navigable brook-sized tributary stream of the Monongahela River in Fayette County, Pennsylvania. The creek is 28.4 miles (45.7 km) long, running from headwaters on Chestnut Ridge north through the city of Uniontown and reaching the Monongahela at Brownsville. Located in a 1/4-mile-wide valley with low streambanks, the site was ideal for ship building in a region geologically most often characterized by steep-plunging relatively inaccessible banks — wide enough to launch and float several large boats, and indeed steamboats after 1811, and slow-moving enough to provide good docks and parking places while craft were outfitting.

Port of Pittsburgh inland port in Pennsylvania, USA

The Port of Pittsburgh is a vast river traffic region in southwestern Pennsylvania. It spans a twelve-county area including Allegheny, Armstrong, Beaver, Blair, Butler, Clarion, Fayette, Greene, Indiana, Lawrence, Washington, and Westmoreland Counties. It encompasses essentially all 200 miles of commercially navigable waterways in southwestern Pennsylvania, including the three major rivers in this region: the Allegheny, the Monongahela, and the Ohio. These waterways are made navigable by a system of seventeen locks and dams. The Port of Pittsburgh supports over 200 river terminals and barge industry service suppliers, including privately owned public river terminals. The port complex is served by the CSX and Norfolk Southern railroads and by four interstate highways. The Port of Pittsburgh Commission acts as a comprehensive service for shippers and industries seeking information on the river system.

Flint Run (West Virginia) river in the United States of America

Flint Run is a tributary of McElroy Creek, 7.5 miles (12.1 km) long, in northern West Virginia in the United States. Via McElroy Creek, Middle Island Creek, and the Ohio River, it is part of the watershed of the Mississippi River, draining an area of 25.6 square miles (66 km2) in a rural region on the unglaciated portion of the Allegheny Plateau.

The Ohio River Water Trail, navigates the counties of Allegheny, Beaver, Columbiana, and Hancock in the states of Ohio, Pennsylvania, and West Virginia. The trail is under the stewardship of the Ohio River Trail Council. The Water Trail or Blueway geographically extends from the Three Rivers Water Trail in Pittsburgh, PA to Newell, WV and East Liverpool, OH. The 69-mile Ohio River Water Trail (ORWT) includes thirteen-miles of the Ohio River along the Three Rivers Water Trail from "The Point" in Pittsburgh at milepost zero downstream to the Dashields Lock and Dam at milepost 13, thirty-three-miles of the Ohio River from Dashields Dam at milepost 13, downstream to Newell, WV at milepost 46.0, sixteen-miles of the Little Beaver Creek to Beaver Creek State Park, three-miles of the Beaver River to the Townsend (Fallston) Dam, and four-miles of the Raccoon Creek.


  1. 1 2 Pennsylvania Gazetteer of Streams (PDF). Pennsylvania Department of Environmental Protection. 2001. Archived from the original (PDF) on 2008-06-25. Retrieved 2008-04-11.
  2. See this map of the Willamette's mouth
  3. Sole, Robert L.; et al. (November 1999). "Lower Mississippi River Ports and Waterways Safety System (PAWSS) RF Coverage Test Results" (PDF). Retrieved 2010-10-08.
  4. "Site: PGHBW 4-3, A View of the Point from Grandview Avenue, Pittsburgh, PA". University of Pittsburgh, Department of Geology. Archived from the original on 2007-07-15. Retrieved 2008-04-11.
  5. 1 2 Allegheny River Chart No. 5 (Pennsylvania, Allegheny County): Twelve Mile Island, Fourteen Mile Island, C.W. Bill Young Lock & Dam Pool (PDF) (Map). 1' - 1500". U.S. Army Corps of Engineers, Pittsburgh District. January 2004. Archived from the original (PDF) on 2007-06-11. Retrieved 2007-08-25.
  6. "Allegheny Islands State Park". Pennsylvania Department of Conservation and Natural Resources . Retrieved 2008-04-11.
  7. Pennsylvania Environmental Council. "Three Rivers Conservation Plan, Chapter One: Project Area Characteristics" (PDF). Pennsylvania Department of Conservation and Natural Resources . Retrieved 2008-04-11.
  8. 1 2 "River Mile System of Ohio". Ohio Environmental Protection Agency, Division of Surface Water. Archived from the original on 2008-06-08. Retrieved 2008-04-11.