A postburn drilling, coring, and geotechnical surveying program was conducted at WIDCo-CRIP underground coal gasification test site near Centralia, Washington. The objective of the program was to delineate the extent of the coal and overburden affected by the gasification test and to provide subsurface information for process analysis. Nineteen holes were drilled. Six were drill holes, four were a combination of drill and core holes, and nine were core holes. Various geophysical logs and surveys were run on each hole. Subsurface samples of coal, overburden, and residues of the gasification test were recovered as drill cuttings and cores.