Nested longitudinal variability in channel width and depth have rarely been included in channel classifications. However, variability in topographic features of rivers, in conjunction with sediment supply and discharge, produces a mosaic of channel forms that provides unique habitats for sensitive aquatic species. We are investigating the utility of topographic variability attributes in distinguishing channel types and dominant geomorphic processes. Initial results indicate that incorporating variance in channel classification provides a quantitative basis for interpreting nonuniform as well as uniform geomorphic processes, which can improve our ability to distinguish linked channel forms and processes of geomorphic and ecological significance. These efforts are now being applied throughout the State of California through partnerships with several academic entities.