Measurements of carbon, nitrogen, and oxygen isotope ratios in the bone collagen indicate that the man lived almost exclusively on a diet of marine mammals for the last 20 or so years of his life and that the water he drank was glacial melt water. The closest marine coastal environment where glacial melt water could have been found at the time of Kennewick Man was Alaska. That, combined with the location of the find, led to the conclusion that the individual led a highly mobile, water-borne lifestyle centered on the northern coast.