The sediments of Little Long (Hiawatha) Lake are described. The lake is surrounded by forest and approximately one-half of the sediments is of organic origin. Water composes approximately between 80 and 90 per cent of the deposits which have a maximum thickness of about 10 feet. Lithification would produce a black carbonaceous or bituminous mudstone which would hardly exceed 2 feet in thickness. The sediments yield from 9 to nearly 12 pounds of oil per ton of dry weight. No stratification was seen in any of the organic-rich, fine-grained sediments.