This report summarizes the results from the subsidence research study completed by the U.S. Bureau of Mines at the Roadside Mine, Powderhorn Coal Co., Palisade, CO. This research was conducted from February 1981 to August 1985, with additional data obtained during July 1991, to evaluate residual subsidence. The Bureau studied subsidence at three distinct room-and-pillar sections at separate locations over the mine and determined the maximum subsidence values and surface subsidence profiles for each mining section. Maximum subsidence of 3.0 ft. occurred over the room-and-pillar sections, with over-burden depths ranging from 50 to 600 ft. Surface tension cracks had occurred, and were still evident during the residual subsidence survey.
United States Department of the Interior, Bureau of Mines, "Surface Subsidence Over a Room-and-Pillar Mine in the Western United States" (1993). Mines and Mineral Resources. Paper 3.