The St. Marys River, a Great Lakes Area of Concern, suffers from a history of development for shipping and industry. Alteration of flow regime and substrate resulted in 90% habitat loss, including the Main Rapids and Little Rapids, with subsequent degradation of fish and macroinvertebrate communities. A $9 million project was funded by NOAA to replace two undersized culverts with a 600’ bridge to return flow to the Little Rapids area and reverse ecological impairments. The goals were to restore higher current velocities for native fish spawning (e.g., Lake Whitefish), and increase fish and macroinvertebrate diversity. We monitored water quality, macroinvertebrates, and larval, sub-adult, and adult fishes in the Little Rapids area pre-restoration (2013-2014) and post-restoration (2017). Pre-restoration monitoring revealed a diverse assemblage of fishes, but 98% of species caught were common in lentic systems and few sport fish were observed. Natural reproduction of salmonids was observed, but it was five times less in the Little Rapids than in the Main Rapids, a remnant rapids habitat in the river. The macroinvertebrate community had low diversity and species were indicative of poor to moderate habitat quality. Post-restoration monitoring is ongoing in 2017, but restoration of flow in the Little Rapids is expected to increase sport fish populations and macroinvertebrate diversity, contributing to the long-term goal of delisting the St. Marys River as an Area of Concern.