Hyporheic communities of two montana rivers.

Collections of stream organisms from a domestic water supply system adjacent to the Tobacco River revealed that a detritus-based community exists in subterranean waters circulating through floodplain gravels at least 4.2 meters below and 50 meters laterally from the river channel. Several stone fly species spend their entire nymphal life cycles in underground habitats of the Flathead and Tobacco rivers.