Coal Mine Subsidence near Sheridan, Wyoming. Surface subsidence effects above abandoned coal mines 10 to 15 kilometers north of Sheridan. Subsidence pits and troughs above the Dietz Coal Mines in operation from the 1890's to the 1920's. Coal was mined from three different beds. The mine workings, which were abandoned in the early 1920's, are locally superimposed. The overburden comprises weak claystones, shales and local thin, soft sandstones. Its thickness is estimated to range from 5 meters along the margins of the subsidence area to as much as 45 meters. Pits and troughs located in draws draining into Goose Creek disrupt or divert surface water to old mine workings. The Bighorn Mountains are in the far background. October 1976. Frontispiece B, U.S. Geological Survey Professional Paper 1164.
Digital File:dcr00007

ID. Dunrud, C.R. 7cp