A comprehensive analytical scheme for the chemical, mineralogical and physical property characterization of coal cores has been developed. The scheme includes the determination of those properties that are important in the evaluation of the burning characteristics of coal, and will thus aid in the selection of areas favorable for underground coal gasification and in the optimization of this in-situ energy extraction process. Four coal cores were analyzed, two from a western underground coal gasification site near Hanna, Wyoming (Carbon County) and two from an eastern site near Pricetown, West Virginia (Wetzel County). To obtain a valid seam evaluation, analyses were obtained on 148 samples representing the total column of the coal interval from each of these four cores. From the analytical data, average properties for the coal interval of each core were derived for use in site-evaluation studies and for correlation with important operating parameters in the underground gasification tests at these sites. Results are also presented for an additional nine samples selected from a fifth coal core taken at the Hanna, Wyo. site. The compositional heterogeneity found by vertically sampling the entire coal column at the selected sites demonstrates the importance of carrying out detailed core analyses for an adequate bed assessment. On the other hand, the lateral continuity in chemical and mineralogical composition observed for the coal deposits at both the western and eastern sites indicates that stratigraphic variations are systematic and therefore predictable. (auth)