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INTRODUCTION The research described in this report is part of a com- prchcnsivc effort by the U.S. Bureau of Mines to develop a subsidence data base representative of western U.S. min- ing conditions. This data base will provide researchers and mine operators with the information needed to further un- derstand the effects of subsidence. This understanding is needed by mine operators to predict how mining and geo- logic parameters affect the inagnitude and extent of sub- sidence in the West, thereby allowing for a mine design that will avert or limk the adverse effects of subsidence. In 1977, Congress passed the Surface Mining Control and Reclamation Act. Section 516 (5) (1) of the act re- quires the operator to '_adopt measures to prevent sub- sideacc causing material damage ' Therefore, a meth- odology to predict subsidence is needed by mine operators to avoid or mitigate damage resulting from mining. Exten- sive information exists regarding subsidence research in the Appalachian and Illinois coal regions of the Unkcd States (1)? however, information retarding subsidence research in the West is limited. Western coal mining conditions include strong massive sandstone member%, thick and multiple coal scams, and extreme variations in overburden thicknesses, and while research efforts have been initiated by the Bureau (2-5), a complete data base docs not exist that fully addresses subsidence prediction and control technologies in the West. The Bureau's research program is directed toward ful. filling the needs of industry in the prcmining evaluation of subsidence impact potential and in facilitating the per- mitting process. The immediate benefit to the mining industry from the completion of addkienal western U.S. subsidence research studies is a much more accurate and quantitative understanding of the behavior of subsidence occurring over room -and -pillar and longwall operations in geologic conditions unique to the West. The ability to predict subsidence and associated damage will allow twine operators to extract resources that arc currently sterilized because the technology docs not exist to predict the result• ing surface subsideoce effects to the degree necessary to ensure that adverse impacts can be minimized. This case study was one of several conducted by the Bureau that together would begin to provide the subsid- ence data necessary to characterize western U.S. mine subsidence. Once general subsidence parameters an be estimated, the potential impacts of the subsidence can be evaluated. The apabdi y to conduct this type of evaluation will bene- fit mine operators and regulatory agencies that must assess subsidence impacts. The major objectives of this study were to (1) present measured surface subsidence caused by room -and -pillar mining in the Cameo V coal scam; (2) determine the tiniusg, rate, and areal extent of subsidence; (3) estabksh the final subsidence profiles; (4) correlate mining and geologic variables with measured subsidence values; and (5) evaluate the long-term residual subsidence. This particular site was selected for the following reasons: (1) coal is mired by the room-and-piNar method; (2) shallow sandstone overburden was present throughout the study site; and (3) several structures and two streams were undermined. ACKNOWLEDGMENTS The Powderhorn Coal Co. provided valuable assistance in conducting this research. In particular, mine engineers William Poloske and Larry Rcschkc have made: significant contributions to the project. Without the access they SITE SELECTION provided to company property, mine plans, survey data, drill logs, and other information relating to the Roadside Mine, this study could not have been conducted. ROADSIDE MINE STUDY SITE The Bureau selected the Roadside Mine to monitor subsidence because the sift had specific mining and overburden features for which little or no subsidence field data exist, including shallow sandstone overburden, full r Iahc numkem to parentheses refer to items to the list or references to Ike end or tha report, extraction room -and -pillar mining, and two streams. The sits also has manmade structures (pipelines, power lines, and water storage tanks) overlying the mine. SITE DESCRIPTION The Roadside Mine is located on Federal and private coal leases approximately 4 mNes northeast of Palisade,