We present data on freshwater mussel (Mollusca: Bivalvia: Unionidae) distributions for Tinkers Creek, a small Ohio stream that previously had not been surveyed for its unionid fauna. The distribution of these mussels was mapped against the changing habitat of the stream, with special attention paid to two zones of human manipulation, a wastewater treatment plant and a stretch of the river where the bed was relocated to enable development. At least five unionid species live in Tinkers Creek. These are Pyganodon grandis, Lampsilis radiata luteola, Fusconaiajlava, Lasmigona costata, and Lasmigona compressa. Fresh shells suggested the presence of three others: Strophitus undulatus, Toxolasma parvus, and Alasmidonta marginata. The region of Tinkers Creek where the mussels are most common extends through Twinsburg, Ohio, and upstream to a waterfall just below the confluence with Pond Brook. Relocation of the river channel eliminated mussels from a 0.5 km stretch in eastern Twinsburg. Furthermore, the impact of effluent from a wastewater treatment plant was minor, at most. Mussel diversity diminished from five to three species commonly found below this facility. A change in river habitat to faster flow, however, provided an alternate explanation for this faunal change. The most striking difference was the replacement of Lasmigona costata, a species usually found in medium and large rivers, by L. compressa, a species common in small streams and headwaters.