We’ve been addressing the spatial distribution of fishes in the Upper Green River Basin of central Kentucky and their relationship to watershed- and reach-scale environmental parameters. Previous data analyses performed within individual subbasins showed that fish distribution was influenced mainly by watershed size and stream size characteristics (e.g., percent pool habitat) and not by land-use patterns or other indicators of anthropogenic disturbance. Several fish species were associated mainly either with small, upland segments or conversely only within the largest, deeper segments. The latest analyses have including data from an additional subbasin, pooled data across all subbasins, but divided sites into two distinct watershed groups to assess if there were size-driven biotic responses to environmental variables. We exposed species abundance and environmental data for the two stream groups to canonical correspondence analysis (CCA) in a forward selection procedure to reduce the number of variables. However, even after attempting to control for watershed size most variables (e.g., discharge, percent pool) elucidated in the second CCA were stream size-related.  In addition, Pearson correlations between the abundances of species selected through indicator species analyses and the all environmental variables resulted in several significant analyses but nearly all were related to stream size.