Like most major rivers and cities in Ohio, the Mahoning River and its watershed have played a significant role in the development of the city of Youngstown located in the northeast corner of the state.

There is little known of the area we call the Mahoning Valley prior to the white man’s arrival in the mid 1700’s. Most information is speculative at best. According to Joseph Butler, a 1921 historian, “there is neither history nor reliable tradition concerning the inhabitants of the vast territory north of the Ohio River and west of the Alleghany Mountains prior to that time” (1). The area was a lush, fertile flood plain that beckoned tribes of Native Americans passing through from the Ohio River north to settlements located by Cleveland and Detroit.

The name “Mahoning” is derived either from the Native American word Mahoni, signifying “a lick,” or Mahonink, “at the lick”.

Relevant articles


  • Quick Facts of the Mahoning River
    • Formed near Winona in Columbiana County
    • Total Mileage is 113 Miles
    • Travels through, Columbiana, Stark, Trumbull, Mahoning Counties in Ohio & Lawrence County in PA.
    • Total of three major reservoirs are made on the Mahoning River. On the west fork is West Branch Reservoir. On the east fork are the Berlin Reservoir and Lake Milton.
    • Three major tributaries make the Mahoning River. West Branch of the Mahoning, Eagle Creek, & Mosquito Lake/Creek.
    • The first two recorded Muskie fish captured in Ohio was from the Mahoning River. In two spots (Lowellville & Braceville)
    • 1913 was the Epic flood of the Mahoning River (water was reported to be at least 6 ft. deep inside of the B&O station.)

About the Mahoning River

The Mahoning River Watershed is located in northeast, Ohio and extends into five surrounding Ohio counties including Portage, Stark, Mahoning, Trumbull and Columbiana. The Mahoning River watershed occupies 1,133 square miles of land area and is fed by many tributaries and streams. A few of the main tributaries include: Meander Reservoir, Mill Creek, Yellow Creek, Crab Creek and Mosquito Reservoir. There are no natural lakes in the watershed, but many have been built along the tributaries to provide water for various uses.

After the river leaves Mahoning County, it flows south into the Ohio River and the Mississippi River, eventually entering the Gulf of Mexico. The river was a major attractant for colonization of the area and set the stage for population and industrial growth in the nineteenth and twentieth centuries.

Rise of the Steel Industry

In 1803, the Hopewell Furnace was erected by Daniel and James Eaton who contracted for the rights to dig coal along Yellow Creek. Competitors John Struthers and Robert Montgomery also built a furnace a short distance away. These furnaces marked the beginning of the iron and steel industry of the Mahoning Valley.

Youngstown’s population and the steel industry grew throughout the 1800’s. During the heyday of industry, the river would serve as both a coolant for molten steel and a drinking water source for the growing Youngstown population for many years.

Several low-head dams were also built along the Mahoning River by the steel industries to increase the availability of water for cooling the hot steel and machinery (the used water was often 100 degrees and filled with chemicals, when it was poured directly back into the river).

During the many years the mills were running, most of these toxins were washed downstream to the Beaver and Ohio Rivers, although some of the toxic sediments settled on the bottom of the Mahoning River and have accumulated in large amounts behind the low-head dams.

In 1977, the EPA released a list of the toxins being poured into the Mahoning River when the nine major steel mills were running. They included: 400,000 pounds per day of suspended solids, 70,000 pounds per day of oil and grease, 9,000 pounds per day of ammonia-nitrogen, 800 pounds per day of zinc, 600 pounds per day of phenolics and 500 pounds per day of cyanide.

The list of contaminants in the Mahoning River include heavy metals (mercury, lead, zinc, copper, cadmium, silver and iron), grease, oil, organic compounds, PCB’s and PAH’s, pesticides, and other organic toxins and carcinogens. In addition, there was thermal pollution, as the water was drawn from the river and used as a coolant for steel and machinery. It was then put back into the river at 100 plus degrees Fahrenheit.

Steel Operations Shut Down in the 1970s

On September 19, 1977, a day that was to be remembered in Youngstown as “Black Monday”, one of the largest steel operations in the area would close and over 4,100 workers lost their jobs. This would mark the beginning of the end of steel-making for the city of Youngstown and adjacent communities. After this initial closing, other plants followed, and most were gone by 1982. The steel industry, which had sustained the economy and flourished in the area for over 100 years, had collapsed.

The closing of the steel mills in Youngstown was devastating to the economy.  When the mills shut down, Youngstown lost over 40,000 manufacturing jobs and $414 million in personal income. In 1950, the height of the population was 160,000 and by 2010 it was less than half at 66,982.

Industry’s End Meant Potential for the River

The mill closings, although bad for the economy of the Mahoning Valley, were a blessing for the Mahoning River. It brought an immediate stop to the continuous pollution from steel manufacturing and the river waters began to recover.

Acres of brownfields, abandoned land areas left after heavy industrial use, are left where the mills once stood. They often contain old parking areas, building foundations, trash and a variety of soil contaminants from the former industry use. In order to be able to reuse these fields, they must be properly assessed and remediation projects put into place.

There is now a genuine concern for the Mahoning River and the important role it will play for any future plans. The river, which was once viewed as a necessary, heavily polluted evil that allowed for steel production, is now seen as an important and underused natural resource worth preserving.