Evidence that drainage basin morphology and trout standing stock are related through a functional link between geomorphic features and stream habitat quality is presented. Numerous significant univariate correlations were found between geomorphic variables, stream habitat variables, and trout standing stock in both high-elevation forest and low-elevation rangeland streams. Canonical correlations between geomorphic variables and stream habitat variables provided insight into the form of the functional link. Multiple-regression equations predicting trout standing stock were dominated by geomorphic variables. When geomorphic variables alone were incorporated into regression models they predicted trout standing stock as accurately as did stream habitat variables.