River in N W.Va. & SW Pa., flowing north to join the Allegheny at Pittsburgh & form the Ohio River: 128 mi (206 km)
The principal districts are the Fairmont (or Upper Monongahela) and the Elk Garden (or Upper Potomac) in the northern, and the Pocahontas (or Flat Top) and the New and Kanawha rivers districts in the southern part of the state.
Natural facilities for transportation, afforded by the Ohio river and its branches, the Monongahela, at the northern end of the state, and the Little Kanawha and the Great Kanawha, are of special value for the shipment of lumber and coal.
The Monongahela has been improved by locks and dams to Fairmont.
CHARLEROI, a borough of Washington county, Pennsylvania, U.S.A., on the Monongahela river, near the S.W.
of the Ohio, and to the eastward, between the Monongahela and the Kanawha rivers, but the grant was never actually issued.