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ENDANGERED SPECIES 371 annually in the Gila, Salt, and Verde river drainages, Arizona. Reintroduction of Colorado squawfish in the Salt and Verde river drainages began in 1985, and desert pupfish and Gila topminnow have been stocked at several reintroduction sites in Arizona. Success of these reintroductions has yet to be fully evaluated, but the programs are expected to continue and expand to other lower-basin locations. To date, most work on native fishes in the upper basin has been oriented toward research and population monitoring, in part because river habitat degradation is less severe, and wild populations of federally protected and rare fishes are still present. Plans for reintroducing upper-basin endangered fishes incorporate and depend upon understanding population genetics and on habitat enhancement or restoration. A program has been developed to recover, delist, and manage humpback chub, bony tail, Colorado squawfish, and razorback sucker in the upper basin while allowing for additional water development (Wydoski and Hamill 1991). Elements ofthe recovery program are (I) provision of instream flow-determine, procure, and maintain instream flows required to protect and recover the species; (2) habitat development and maintenance-increase the amount of favorable habitat for reproduction, production, and overwintering; (3) artificial propagation and stocking of rare and endangered fish species; (4) nonnative species and sportfish- ing management-regulate stocking of nonnative fishes, selectively remove nonnative species, regulate sportfishing in areas where rare and endangered fishes occur, and educate the fishing public on rare and endangered fishes; and (5) research, monitoring, and data management. The time frame for this $60 million recovery program is 15 years, and an Upper Colorado River Recovery Implemen- tation Committee oversees recovery efforts. Even with operating recovery strategies in place, the future of the Colorado River's native fishes appears bleak. Carlson and Muth (1989) concluded that conflicts between development and natural ecosystems in the basin will continue and probably worsen as demand for water increases. Stanford and Ward (l986a) stated that the river's future depends on whether (1) there will be enough water to maintain desirable ecosystem values and (2) native and nonnative fishes can coexist. They concluded that the endangered fishes are incompatible with stream regulation and nonnative species and that future water shortages will preclude allocations for them and other ecological concerns. 15.4.5 Western Trouts in the lGenus Oncorhynchus Since the turn of the century, most native western trouts have experienced declining populations, and some species have been pushed to near extinction (Ono et al. 1983). Behnke (1992) classified native western trouts into four species and 22 subspecies. Five are federally listed as threatened (Little Kern golden trout, Apache trout, Lahontan cutthroat trout, Paiute cutthroat trout, and greenback cutthroat trout), and one is federally listed as endangered (Gila trout). Other native western trouts are variously protected by several western states and often appear on unotJiciallists of threatened and endangered fishes. Some of these, such as Colorado River cutthroat trout and BonneviUe cutthroat trout, are under review for federal listing. Several factors have contributed to the decline of native western trouts. One ~