Abstract

The Wyodak-Anderson coal zone in the Powder River Basin has been studied as part of the U.S. Geological Survey's National Coal Resource Assessment (NCRA), a national study of coals with the highest potential for development within the next 20 to 30 years. The assessment was driven by the need for clean, compliant energy sources. More than 30% of the Nation's 1997 total coal production of 1.09 billion short tons (Energy Information Administration, 1998) was produced from 14 Tertiary coal beds and zones in the Northern Rocky Mountains and Great Plains region (figure 1). The highest coal production in the region is from the Wyoming part of the Powder River Basin, primarily from coal in the Wyodak-Anderson (WA) coal zone.

The coal beds and zones studied for the NCRA in the Powder River Basin are the Wyodak-Anderson in Wyoming and Montana, and the Anderson-Canyon, Knobloch, and Rosebud-Robinson in Montana. The Wyodak-Anderson coal zone, as defined for our study, includes the Anderson, Dietz, Canyon, Monarch, Werner, Wyodak, Smith, Swartz, Sussex, School, and Badger coal beds.

A major part of the assessment of WA coal was to compile all available data, correlate the beds that make up the WA coal zone, and creat digital files pertaining to the coal and the study area. Coal resource calculations in this report were produced using both public and confidential data from many sources. Data were manipulated using a variety of commercially available software programs and several custom programs. This paper includes a general description of the methods used for the calculation of coal resources and tables reporting the coal resources of the WA coal zone by state, overburden, coal thickness, and reliability categories, county, Federal ownership, and 7.5-minute quadrangle.

Any use of trade names in this document is for descriptive purposes only and does not imply endorsement by the U.S. Government. Additionally, no proprietary data is being released in this document.