The Bill Williams and Hassayampa river drainages in west-central Arizona were surveyed during the winter and spring of 1980. The purpose of the study was to provide aquatic habitat and water quality baseline data for management planning of aquatic resources on public lands. Included in this report are descriptions of existing aquatic habitats, analyses of water quality, and distribution and quantification of aquatic invertebrate and fish populations. Chemical and physical water quality was generally within acceptable state and federal standards for surface waters, except in local situations involving copper mining operations. Quantitative sampling of macroinvertebrate communities revealed a general paucity of invertebrates. Surber invertebrate samples were largely dominated by chironomid dipterans. Museum records combined with field collections indicate at least 20 species of fish collectively occur over both drainages. More than 84% of the total fishes collected were native species, of which longf in dace (Agosia chrysogaster) were numerically dominant. Of four habitat types analyzed, backwaters supported the highest densities of both native and introduced fish. Riffles were least productive, but were found to provide preferred habitat for certain species of fish, i.e. Gila mountain-sucker (Pantosteus clarki). Management recommendations designed to enhance and maintain aquatic resources on the Harcuvar, Vulture, and Skull Valley planning units arediscussed based on inventory data.