A prominent (> 7000 nT), multi-featured, and also geomorphically expressed aeromagnetic anomaly of undoubted prime exploration potential was discovered within the Yumbarra Conservation Park as a result of detailed low level aeromagnetic surveys undertaken as part of the South Australia Exploration Initiative during 1992. The approximately 10 square km central part of the park was reproclaimed in November 1999 to allow mineral exploration under strict guidelines. Prior to grant of the Exploration Licence, baseline biodiversity studies were carried out and aboriginal site clearances were obtained. Initial work done on the licence comprised detailed airborne geophysical surveys and data modelling, which reinforced the interpretation of the magnetic anomaly as a layered mafic-ultramafic intrusive lying at a depth of only about 50 m, which could have strong potential for hosting nickel, copper and platinum group elements mineralisation. Subsequently, the acquisition of 77.3 line km of airborne (TEMPEST) and ground based EM and IP surveys failed to delineate significant bedrock conductors. Regional calcrete and soil geochemical sampling delineated several prospective areas which were followed up during 2001 by auger sampling of the regolith and by aircore drilling to bedrock (55 holes, total 1220 m). The latter drilling encountered a suite of felsic to ultramafic intrusive rocks, and returned peak trace metal values of 1066 ppm Co and 1357 ppm Ni, with coincident high iron values to 36% Fe. It was concluded that a layered mafic-ultramafic intrusive body is indeed the likely source of the magnetic anomaly, having prospectivity for copper-nickel and PGE mineralisation rather than for gold.