We characterized coldwater stream fish community response to habitat degradation and channelization for agriculture. Coldwater streams are not common in the lower midwestern United States, and these streams differ from warmwater streams with respect to their diversity and community response to degradation. Six sites were sampled on the coldwater Mac-o-chee Creek in Ohio. Three reaches were classified as geomorphically constrained (by a roadway) and three as recovering (unconstrained and not channelized or cleaned for more than 100 y). Within each reach 31 mesohabitat units were sampled and were delineated as riffles, runs, or pools. Our goals were: (1) to examine how habitat and geomorphic impairment influences the abundance and community structure of coldwater fishes; and (2) to test whether the constraints on recovery from channelization were more influential in structuring communities than mesohabitat types. Our hypothesis was that we would find lower species diversity overall in the recovering sites because they would be more indicative of a coldwater fauna. In contrast, we hypothesized that the sites that are not able to recover (geomorphically constrained) would be more indicative of a warmwater fauna, and thus more diverse. We found lower species abundances, diversity, and species richness in recovering stream reaches than impaired reaches. Mesohabitat types present are influenced by channelization and recovery but are also largely a product of geomorphologic setting of the study streams. The effects of habitat degradation on the biota and the resulting trophic structure are important for designing restoration targets for coldwater systems, which may be naturally less diverse than warmwater counterparts. For example, biometric scores like Index of Biotic Integrity (IBI) are often used as restoration targets, but this would be inappropriate unless a coldwater-specific IBI were used.