We document the occurrence of the Bird-voiced Treefrog (Hyla avivoca), at 32 sites in the upper Ouachita River system of Arkansas, including specimens from the Little Missouri and Saline River tributaries. This more than doubles the total number of sites from which this frog is known in Arkansas, and the distributional limit coincides with the interface of the Ouachita Mountains and the Gulf Coastal Plain. West of the Mississippi River, only a few localities are known for this species in Oklahoma and Louisiana, making the Arkansas populations important for the conservation of the species.