The objective of this review was to evaluate the ability of existing models and modeling approaches to explain and predict temporal changes in fish abundance in the Upper Mississippi River System (UMRS) based on environmental factors. Information on models was obtained through a literature review and personal contacts with Federal and academic specialists. Models were evaluated based on their assumptions, data requirements, outputs generated, and applicability to UMRS fishes. Many existing models can incorporate environmental effects on fish populations, but none were developed specifically for large rivers. The models reviewed were of three types: analytical, empirical, and mechanistic. Of these three model types, empirical regression models, developed from UMRS data, would probably be the most useful for addressing questions regarding mean abundance of a species over space or time. Mechanistic population dynamics models have the most potential for following and predicting population or community dynamics and for incorporating empirically determined environmental effects.