As part of a continuing regional search for economic deposits of uranium and other radioactive minerals within alluvial fan sediments deposited adjacent to and east of the Mount Painter Block basement outcrops, 32 rotary holes (total 16,218 feet) were drilled about half-a-mile apart along certain present-day major drainage lines, each to approximately 500 feet; all drillholes were geophysically logged with a gamma ray probe that was run inside the drill string. Minor anomalous radioactivity, to approximately twice background level, was detected in two holes, 221-7 and 221-13, at a depth of about 195 feet within ?Cretaceous sediments. Earlier, a radiation kick of up to 5.3 times background was reported from a depth of 536 feet in hole 221-5, over a 1 foot interval at the Phanerozoic cover/basement contact.