History
The Red Waterfall gets its name from the acidic and iron-rich water that flows off the hillside, through an old railroad culvert under the Great Allegheny Passage, and into the Youghiogheny River from underground coal mines established in 1900 by the Ocean Coal Company, which later abandoned them.
Coal mining exposes iron and sulfur (together, pyrite) to oxygen and groundwater, producing sulfuric acid and a number of red, yellow, and orange compounds. This acid contaminates the groundwater, which seeps out of the mine into streams, and stains the rocks rust-red. Acid mine drainage is a major source of water pollution and the cause of extensive stream degradation and environmental damage.
Visitor Information
The Red Waterfall is between West Newton and McKeesport, and the closest parking is at the GAP trailhead near Sutersville, Pa.