Pottery sherds, stone lamps and artifacts from archaeological sites in Alaska and Canada were selected from the archives of the National Museum of Natural History in Washington DC. Ancient organic residues were collected on the sherds, often incrusted as a thick layer. Lipids were extracted from these residues followed by derivatization and analysis by high temperature gas chromatography (HTGC) and combined gas chromatography mass spectrometry (GC/MS). Modern samples of whales and seals were also analyzed. Some of these fresh specimens were thermally degraded to simulate cooking and aging. Alkaline treatment was sometimes necessary to hydrolyze the insoluble lipid fraction.