In North America, Unionid mussels have exhibited severe declines, and reintroduction represents a valuable conservation tool. Freshwater fishes and mussels have coevolved a relationship whereby fishes serve as hosts for early life stages of mussels (glochidia), and successful recolonization is partially dependent on the ability of fish hosts to successfully disperse to suitable mussel habitat. The Mission Reach of the San Antonio River is an eight-mile (12.8 km) urban stream reach with a particularly ‘flashy’ hydrologic regime, and restoration projects have involved the construction of 31 erosion control structures. These structures have the potential to structurally fragment the riverscape but have yet to be evaluated for fish passage. Although juvenile mussels have been reintroduced, natural recolonization by sexually mature mussels is yet to be documented. One hypothesis for the lack of recolonization success is that movement by fish hosts may be limited by installed structures or the unique hydrology, thereby reducing connectivity between established mussel populations and suitable rearing habitat. Our objective was to determine whether individual fish are successfully passing erosion control structures and evaluate potential predictors of passage. We used passive integrated transponder (PIT) tags to evaluate movement across a subset of seven structures within the Mission Reach. We PIT tagged 1,140 individuals representing 20 species and used a mobile antenna system to redetect individuals biweekly from May to August in 2024. We redetected 229 individuals and documented 22 passage events. Passage was correlated with fish length, multiple structure-specific characteristics, and Julian date, indicating that larger (and most likely older) individuals pass structures more frequently and that passage declined over the course of the summer months. Our results will be used to inform future mussel reintroduction efforts and indicate that structures comparable to those in the Mission Reach do not represent complete barriers to movement by fishes.