Southeastern U. S. river waters are more or less immediately derived from meteoric waters percolating through soils and swamps. For this reason, they carry dissolved organic matter eluted from the soils and swamps. There is some evidence that the main constituent of river water organic matter is humic material. River water organic matter from Georgia's Satilla River, obtained by freeze-drying the river water samples, was fractionated by gel permeation chromatography (GPC) into three molecular weight fractions. Both the unfractionated river water organic matter and the GPC fractions were characterized by chemical analysis of acidic functional groups (total acidity, carboxyl groups, and phenolic hydroxyl groups). The material was also characterized by IR and NMR spectroscopy. The spectra are comparable to those of soil fulvic acids, but are distinctly different from the spectra of humic acids. The unfractionated material was hydrolyzed and the hydrolyzate was analyzed for amino acids.