The C₁₅₊ hydrocarbons in 220 surface sediments from the outer continental shelf of Alaska were analyzed as part of an environmental survey supervised by National Oceanic and Atmospheric Administration and Bureau of Land Management. Gas chromatography and gas chromatography-mass spectrometry were employed for the identification of organic compounds in the bitumen extracts. Surface sediments from one station in southeastern Bering Sea and two stations in lower Cook Inlet display n-alkanes and triterpenoid distribution typical of weathered petroleum. Major faulting in the vicinity of the southeastern Bering Sea station may account for the leakage of petroleum from subsurface reservoir rocks. Oil production in upper Cook Inlet, or a hitherto unrecorded seep in the rea, could contribute petroleum hydrocarbons to the sediments from the two stations in lower Cook Inlet. Apart from these stations, there is little evidence of near-surface petroleum seeps in the sites investigated.