Gallery: Powder River Coal: 2870_0214

The red material used on the roads is scoria, the residue from ancient underground coal fires.  It is as common as coal in the PRB, and is makes exceptional road base because of its hardness and compactability.

The red material used on the roads is scoria, the residue from ancient underground coal fires. It is as common as coal in the PRB, and is makes exceptional road base because of its hardness and compactability.