The western yellow-billed cuckoo, Coccyzus americanus occidentalis, typically nests in mature riparian forests and woodlands along central and southern Arizona drainages and locally along the Virgin River. Riparian habitat alteration from vegetation clearing, stream diversion, water management, agriculture, urbanization, overgrazing, and recreation has caused drastic reductions in the breeding range of the yellow-billed cuckoo over the last 60 years (Laymon and Halterman, 1987). As a result, western yellow-billed cuckoos have been petitioned for listing under the Endangered Species Act (1973 as amended). To facilitate current species censusing and monitoring activities, a GIS and concomitant correlation models are relied upon to delineate potential yellow-billed cuckoo habitat and to help determine cost-effective field data collection strategies. Initially, GIS and modeling efforts were constrained to legacy data sets such as existing GIS layers of environmental data and historic breeding locations of western yellow-billed cuckoos in Arizona. Eventually, these course-scaled methods for identifying potential locations of yellow-billed cuckoo breeding habitats will be refined to include higher resolution spatial data and a wider array of important secondary database attributes required to succinctly define habitat requirements.