Abandoned Deep Coal Mine
In addition to abandoned surface coal mines, there are a number of abandoned underground coal mines in Moraine State Park. All have been sealed to try to prevent acid mine drainage from entering the lake, but evidence of the mines' former existence is still present.
The small channel in this photo carries a small amount of water from a seep from the sealed mine.
The sandstone boulders covering the slope were removed from the underground mine and dumped on the surface of the hill above the bicycle trail.