Ohio River Basin

The River Alert Information Network (RAIN) Basin is located within the Ohio River Basin

  • Ohio River Basin encompasses approximately 204,430 square miles (130.5 million acres); and over 27 million people live within the Ohio River Basin -- almost 10 percent of the U.S. population.
  • The RAIN Basin is comprised of  the entire Allegheny River Basin, Monongahela River Basin, Beaver River Basin and the first 36 river miles of the Ohio River.

Rivers Within the RAIN Basin Area

The ALLEGHENY RIVER runs 295 miles through Pennsylvania and New York. The watershed basin drains approximately 11,770 square miles in the northern Allegheny Plateau providing the northeastern most drainage in the watershed of the Mississippi River. The Allegheny Valley has extensive deposits of coal, petroleum and natural gas, making it one of the most productive areas of fossil fuel extraction in the nation’s history. The Allegheny River ends in Pittsburgh where it meets the Monongahela River to form the Ohio River.The Monongahela River—or the “Mon”—flows in a northerly direction from the confluence of the Tygart Valley River and West Fork River in Fairmont, WV.

[see Allegheny River Map]

In Pittsburgh, the MONONGAHELA RIVER (know locally as "The Mon") converges with the Allegheny River to form the Ohio River. The Mon is 116 miles long, draining approximately 7,340 square miles of the Allegheny Plateau in north-central West Virginia and southwestern Pennsylvania. Two of its major tributaries are the CHEAT RIVER, which joins at Point Marion, PA, and the YOUGHIOGHENY RIVER, which joins at McKeesport, PA. During the 19th and 20th century, the Mon was heavily used by industry with several U.S. Steel plants built along its banks. According to the U.S. Army Corps of Engineers, acid mine drainage from coal mining has been identified as the factor having the most widespread effect on river water quality in both the Allegheny and Monongahela River Basins.

[see Monongahela River and Youghiogheny River Maps]

Located in northwestern Pennsylvania and northeastern Ohio, the SHENANGO RIVER joins the MAHONING RIVER in Lawrence County, PA, to form the BEAVER RIVER. The Shenango River is approximately 92 miles long, with a watershed draining approximately 1,066 square miles. Agriculture and forestry dominate land use within the Shenango River watershed. The Beaver River is approximately 22 miles long with a watershed draining approximately 91 square miles of diverse urban and rural communities. The river flows through an historically important coal-producing region north of Pittsburgh.

[see Shenango River and Mahoning River maps]