Looking downstream at calm waters of the Ohio River, trees overhanging the water with red, orange, yellow and green fall foliage.
Ohio River A view down the Ohio River in Autumn © Kent Mason

Stories in Ohio

Charting the Course of a River's Future.

The Ohio River is born in Pittsburgh, where waters of the Allegheny and Monongahela Rivers merge.

The Ohio River is born in Pittsburgh, where the Appalachian mountain waters of the Allegheny and Monongahela Rivers merge. Nearly a thousand miles later, the Ohio meets up with the Mississippi, at the aptly named Cairo (think Nile), Illinois.

Along the way, as it snakes through the heart of the country, the Ohio River picks up tributary waters from 14 states, where topography ushers highland waters down a diverse gradient of forest, grassland, farmland and development.

Why It Matters

The Ohio River has always been a work horse for people—providing us with food and water, guiding exploration and settlement, powering early industrial development, and serving as a destination for outdoor recreation. 

In spite of the demands put on it, the system supports abundant wildlife as well.  In fact, the Upper Ohio River Basin has the highest diversity of fish and freshwater mussel species of any river system in the northeast United States, boasting ancient paddlefish and freshwater mussels of such diversity and numbers they have been used to re-establish threatened populations in other states.


Anyone who loves rivers knows they are not static systems. Rivers experience seasonal changes that can transform a calm stream into a raging torrent. Many species of plants and animals have evolved to take advantage of this constant change. Hundreds of species feed in the riffles of the Ohio River basin, nest on its islands, establish roots in its floodplains, and live in or along its banks. These species have evolved over thousands (or, in the case of the American paddlefish, millions) of years, to take advantage of the food and habitat diversity provided by the river’s natural, seasonal variance.

But the Upper Ohio and its tributaries no longer flow naturally. Their currents and volume are managed by dozens of dams to provide us with hydropower, navigation, water supply, flood protection and recreation.

Dams disrupt the natural ebb and flow of a river. They often reduce high flow events that provide a stimulus for fish spawning and rebuild important stream habitat.  Dams also can create a barrier for migrating fish like sturgeon and paddlefish.

In addition, the basin’s rivers and streams are being tapped at historic rates to meet the demands of the growing shale gas industry, further altering the natural flow of these important aquatic habitats.

What We’re Doing

  • Reducing the impacts of dam operations on rivers and streams in the Upper Ohio River basin by working with the Army Corps of Engineers to modify the operation of certain reservoirs in order to encourage native fish passage and help prevent the spread of non-native, invasive fish species like Asian Carp.
  • Expanding the 4R Nutrient Stewardship Certification program into the Ohio River Basin in order to decrease algal blooms.  The 4R program engages growers on best management practices for fertilizer application to reduce excess nutrient runoff into waterways. 
  • Developing natural solutions to flood-handling and harmful algal blooms.