Gregory L. Gunther Romeo M. Flores Allen M. Ochs Gary D. Stricker Steven B. Roberts Thomas T. Taber Lisa R. Bader John H. Schuenemeyer Margaret S. Ellis 1998 The National Coal Resource Assessment (NCRA) project by the U.S. Geological Survey is designed to assess US coal with the greatest potential for development in the next 20 to 30 years. Coal in the Wyodak-Anderson (WA) coal zone in the Powder River Basin of Wyoming and Montana is plentiful, clean, and compliant with EPA emissions standards. This coal is considered to be very desirable for development for use in electric power generation. The purpose of this NCRA study was to compile all available data relating to the Wyodak- Anderson coal, correlate the beds that make up the WA coal zone, create digital files pertaining to the study area and the WA coal, and produce a variety of reports on various aspects of the assessed coal unit. This report contains preliminary calculations of coal resources for the WA coal zone and is one of many products of the NCRA study. Coal resource calculations in this report were produced using both public and confidential data from many sources. The data was manipulated using a variety of commercially available software programs and several custom programs. A general description of the steps involved in producing the resource calculations is described in this report. application/pdf 10.3133/ofr98789A en U.S. Dept. of the Interior Preliminary report on coal resources of the Wyodak-Anderson coal zone, Powder River Basin, Wyoming and Montana reports