Seventeen streamflow-gaging stations, operated by the U.S. Geological Survey and distributed across the Ouachita Mountains of Arkansas and Oklahoma were selected for analysis. Regional hydraulic geometry curves relating drainage area to bankfull dimensions -- cross-sectional area, top width, mean depth, and streamflow -- were developed from data collected at the selected streamflow-gaging stations. Bed material sampling was conducted to obtain information on the particle-size distributions of the streambed materials and to determine the shapes of the individual particles comprising the streambeds. The stream reaches at each stream gage location were classified using the Rosgen Level II stream type (Rosgen, 1996) based on the average of stream channel metrics collected from site cross-sections and profiles. References Rosgen, D.L., 1996, Applied river morphology: Pagosa Springs, Colorado, Wildland Hydrology Books, 390 p. Child item contains data and supporting metadata related to: 1) Streamflow-gaging stations -- geospatial point shapefile of the 17 selected streamflow-gaging stations 2) Watersheds -- geospatial polygon shapefile of the watersheds above the 17 selected streamflow-gaging stations 3) Streambed particle data -- particle size and shape data collected at the 17 selected stream reaches 4) Site information and photos -- stream geometry, classification, descriptions and photos of the 17 selected stream reaches