The means by which organic matter enters and leaves streams and the rates at which it does so are significant determinants of water quality. This report documents the import, storage, decomposition, and export of organic matter in a prairie stream from natural sources in a watershed on the Konza Prairie Research Natural Area that contains no human activity other than ecological research. This prairie stream has features that differ from streams in forested watersheds. During this one-year study, the headwater channels were ephemeral and drained watersheds vegetated by grasses rather than trees. They received less organic matter from the watershed but retained a larger fraction of it. Intermittent third and fourth order channels flowed through riparian gallery forest in the lower portions of the watershed and received more organic matter than headwater channels. They retained less of it during the period of flow (i.e., more was exported during storm flows) so in situ decomposition was reduced. These exports represent pulses of organic matter loading downstream