A review of publicly available coal quality data during the coal resource assessment of the southwestern part of the Powder River Basin, Wyoming (SWPRB), revealed significant problems and limitations with those data. Subsequent citations of data from original sources often omitted important information, such as moisture integrity and information needed to evaluate the issue of representativeness. Occasionally, only selected data were quoted, and some data were misquoted. Therefore, it was important to try to resolve issues concerning both the accuracy and representativeness of each available dataset. The review processes demonstrated why it is always preferable to research and evaluate the circumstances regarding the sampling and analytical methodology from the original data sources when evaluating coal quality information, particularly if only limited data are available. Use of the available published data at face value would have significantly overestimated the coal quality for all the coal fields from both the Fort Union and Wasatch Formations in the SWPRB assessment area. However, by using the sampling and analytical information from the original reports, it was possible to make reasonable adjustments to reported data to derive more realistic estimates of coal quality.