Exploration of CPL 35 244 at Flat Creek since 1982 has indicated that the most promising sites for opencast mining are limited to a relatively small area in the vicinity of the old mine workings 1, 2, 3. Exposed coal in this zone is usually thick (c.4m) and of good quality, however reliable reserve estimation is prevented by widespread structural and local stratigraphic complications. Subsequent to trenching and sampling in 1984, drilling of the coal measures was recommended as the approriate next step in reserve definition.