The purpose of this report is to document the methodologies used to develop the 1979 Demonstrated Reserve Base (DRB) of coal. All primary source documents used to prepare the 1979 DRB were reviewed. Using the methodologies and documentation found in the 1979 DRB published report as a guide, each of the state-level published reserve estimates were re-derived. In those cases where the estimates could not be reproduced, EIA personnel from the Eastern and Western Energy Data Offices were consulted and the differences, for the most part, were resolved. Throughout this report an attempt was made to describe the information flow that was an integral part of the DRB development. Particular attention and emphasis was given to those instances where deviations from standard, published EIA procedures were used to derive the DRB estimates. The main body of this report summarizes the methodological procedures used to develop each state reserve estimate.