The Arkansas State Highway and Transportation Commission and the U.S. Geological Survey have a mutual interest in flood-frequency and open-channel hydraulics for the economic design of bridges and culverts. This report is a summary of the accomplishments of the cooperative program. Included are plans for future work and a brief description of related water-resources programs of the Geological Survey in Arkansas. Peak stages and discharges were determined for 106 sites. Drainage areas for Ouachita River and Red River basins were determined. Hydraulic analyses were made for five bridge sites. (Woodard-USGS)