As part of a regional search for uranium and other radioactive minerals within alluvial fan sediments deposited adjacent to and east of the Mount Painter Block outcrops, 43 open rotary mud holes (total penetration 21,900 feet) were drilled close to the western shore of the central part of Lake Frome, the holes being spaced about half-a-mile apart along certain present-day major drainage lines. Each drillhole penetrated the sedimentary cover of Recent, Tertiary and Mesozoic strata to approximately 500 feet depth, and was then geophysically logged with a wireline gamma ray probe run inside the drill string. In one area, minor anomalous but weak radioactivity (365 and 460 counts per second) to approximately twice background level was detected in two holes, 243-16B and 243-19A, at a depth of about 420 feet within ?Cretaceous sediments.