During April - May 1967 Electrolytic Zinc undertook a programme of air hammer drilling of 20 vertical, six-inch diameter holes at the Crocker Well uranium deposit. Ten holes totalling 1869 feet were put down on the mineralised section of grid line 3800E at the East Crocker (Well) Central prospect to compare ore block valuation results from drill sample chemical assaying and from downhole radiometric probing, and to check for agreement with the SA Mines Department valuation data based on their previous diamond drilling. Another purpose of the repeat drilling along this traverse was to find out what spacing of holes would be necessary to adequately test an area of this orebody for defining ore reserve calculation parameters. In a separate exercise, ten holes totalling 510 feet were drilled, partly to test two small radiometric anomalies in the East Crocker area, or else to sample the bedrock beneath alluvial cover at sites which had yielded radon anomalies in earlier soil gas sampling. Very little uranium was found in each case.