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EXECUTIVE SUIVIMARY Direction for initiating razorback sucker propagation and augmentation of the upper Colorado River basin within the state of Utah is provided in this document. The current population status and trends, factors limiting natural reproduction, and the risk assessment of reintroduction and augmentation are discussed. Goals and objectives of broodstock development, the breeding strategy, and the location of stocking sites in the upper Colorado River basin within Utah aze described. The recommendations outlined meet the goals and objectives set forth by the Genetics Management Plan (Czapla 1999) and the Endangered Fish Interim Management Objectives for the Upper Colorado River Basin Recovery and Implementation Program (Lentsch et al. 1998). This outlined approach considers size offish to stock, and time of year to release for the most efficient use of grow out facilities. This stocking plan would require facilities with a capacity for grow out of 12,100 kg of fish per year, and could achieve the objectives by year eight. It is recommended that: • Years 1 through 3, razorback suckers be stocked 130 mm and 27S mm in approximately equal masses. • Following this recommendation, in year 1, 110,000 (6,OS0 kg) 130 mm razorback suckers would be stocked in the spring, and 22,000 (6,OS0 kg) 27S mm razorback suckers would be stocked in the fall. • In years 2 and 3, SS,000 (3,025 kg) 130 mm razorback suckers would be stocked in spring, and 11,000 (3,025 kg) 27S mm razorback suckers would be stocked in the following fall. • In years 4 and S, 22,000 (6,OS0 kg) razorback suckers would be stocked in the fall. Evaluation of this stocking plan includes monitoring and mazking/tagging recommendations. Subsequent monitoring will -allow evaluation of relative survival rates of each yeaz class stocked. An estimate of adult population size can be determined as well as levels of natural recruitment contributing to the population. The stocking approach will then be adjusted to meet the needs of the RIP as determined by the Biology Committee. The Bonytail Reintroduction Plan for the Upper Colorado River Basin as well as relevant issues associated with this reintroduction aze briefly discussed (Lentsch et al. 1996). The State of Utah recommends the continuation of stocking 120 mm bonytail as in the past. The lack of genetic variability in bonytail makes the requirement for several family lots unnecessary. Thus, IMO levels should be reached as quickly as possible. It is recommended that the target IMO level for the upper basin bonytail stock as stated in Lentsch et al. (1998) be expanded to apply to each population reestablished. LIST OF KEY WORDS stocking plan, Green River, Colorado River, razorback sucker, bonytail vii