Preliminary Bureau of Mines studies of Mafic igneous rocks collected from the Rabbit Creek area, northwestern Alaska, indicated concentrations of platinum and palladium in five of eight samples analyzed. The samples represent boulders and cobbles of Mafic- Ultramafic rocks from this locality. They are not from outcrop. Petrologically, the samples are crudely to well layered and are troctolitic +- gabbroic in character, with primary igneous Mafic minerals strongly altered. Small patches of interstitial sulfide minerals, including chalcopyrite, bornite, pyrrhotite, pyrite, and covellite, are associated with these altered zones and elsewhere through the specimens. Copper values ranged from 0.1 to 0.3 pct in samples analyzed semiquantitatively; nickel, cobalt, and chromium contents are low. Chemical, mineralogic, and petrographic relationships suggest that the rocks of similar character outcropping in northwestern Alaska could also be considered as prospective for concentrations of platinum, palladium, and copper.