Mining in the Centralia East Quadrangle
Mines operated in the Centralia East Quadrangle from before 1882 until 1963. The earliest mine operated was the Chicago-Sandoval Mine (mine index 2847), and the most recent was the Glenridge Mine (mine index 207). Mining conditions were generally good, with Herrin Coal up to 7 feet thick, and a black shale roof that held up well for the most part. The mines in the area intercepted faults of the Centralia Fault Zone, with displacements up to 35 feet in one mine and 18 feet in another.