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002J25 BmCUTJ:VB SUllllARY Curre..t Spec!..s status. The greenback cutthroat trcut (Oncorhvnchus clarki stomias) is the only trout endemic tc both the headwaters of the South Platte and Arkansas River drainages. Although once abundant, their numbers declined in the late 1800's due to over-harvest and the introduction of exotic trout species. The greenback was extirpated from most of its native range by the early 1900's, and Greene (1937) considered the subspecies extinct. In 1973, two small populations were confirmed that represented approximately 2,000 greenbacks in 4.6 km of stream. The subspecies was listed as "endangered" in 1973, and downlisted to "threatened" in 1978. As a result of recovery efforts, captive broodstocks were established, non-native fish were removed from suitable habitat, greenbacks were reintroduced, stable populations were developed and catch-and-release fisheries were initiated. Greenback cutthroat trout are present in 51 sites that total 100 hectares (247 acres) of lakes and ponds and 146 kilometers (90 miles) of stream habitat. Twenty nine sites are open to catch-and-release fishing and 19 populations are considered to be stable. Seventeen stable populations are located in the South Platte drainage, and two stable populations are located within the Arkansas drainage. These numbers may change as new projects are accomplished. Habitat Requir_ellts and Liaiting Pactors. This species inhabits cold water streams and ccld water lakes with adequate s~ream spawning habitat present in the spring of the year. Limiting factors include other spring spawning trout species that hybridize with greenbacks, and fall spawning species that compete with greenbacks for food and space, combined with over-harvest of greenbacks. Recovery Object!.ve. Delisting. Recovery Cr!.ter!.a. The goal of this Plan is to restore the greenback cutthroat trcut to non-threatened status within its,native range. Delisting cf this subspecies is ccnsidered to be possible by the year 2000. This may be accomplished through maintaining at least 20 stable greenback populations cccupying at least 50 hectares (123 acres) of lakes and pcnds and 50 kilometers (31 miles) of stream. At least five of the stable populations should occur in the Arkansas drainage. Actio..s .eeded, 1. Maintain existing populations of greenbacks. 2. Establish or document, 20 stable populations of greenbacks. 3. Establish captive and wild greenback broodstccks within Colorado. 4. COnduct research on greenback angling programs and stocking programs. 5. COnduct greenback information and education programs. 6. Promote partnerships, and expand efforts to obtain non-agency funding. 7. Prepars a long-term greenback management plan and cooperative agreement. Date of Recovery. 2000. cost of Recovery. $634,000. Hi