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rate of adult razorback sucker (0.70) and the recovery goal abundance buffer of 30%. Domestic-reared razorback sucker will be used to establish new populations in the Upper Colorado and Gunnison rivers or augment existing populations (e.g., Green River system). Stocking domestic-reared razorback sucker will continue until more fish recruit to the adult population through natural reproduction in the wild. As more razorback sucker recruit to the adult population by natural reproduction in the wild, stocking hatchery-propagated fish in the wild should be reduced. For razorback sucker populations to be self-sustaining, adult fish must reproduce and recruitment of young fish into the adult population must occur at a rate to maintain the population at a minimum of 5,800 adults (FWS 2002). At this point, stocking razorback sucker in the wild should be discontinued. The RP has sufficient facilities and associated grow-out ponds to meet the demands of the integrated stocking plans (Czapla 2002). The production of razorback sucker to meet the number identified in the Utah stocking plan requires 2.0 ha (5.0 acres) of hatchery ponds and 4.2 ha (10.4 acres) of leased grow-out ponds. The production of razorback sucker to meet the numbers in the Colorado stocking plan require 7.3 ha (18.1 acres) of leased grow-out ponds. Forty hectares (98 acres) of grow-out ponds are available for use in the Grand Valley near Grand Junction, Colorado (Czapla 2002). Purpose and Objectives The purpose of this study was to evaluate the survival and performance of three different sizes of domestically-propagated and reared razorback sucker following stocking in the Upper Colorado and Gunnison rivers. Domestically-propagated and reared fish included fish raised in hatcheries and grow-out ponds. This was an experimental stocking program aimed at predicting the potential success of subsequent supplemental stockings. Experimental stocking is a legitimate, tool that can used as an action preliminary to the decision of whether restoration or augmentation stocking has a chance of success (Williamson 2001). Experimental stocking can help define restoration stocking as a preferred production strategy. The study goals were to: 1. Evaluate the relation between survival of razorback sucker and size at release into the river, either by stocking captive-reared fish or by producing fish in enhanced flooded bottomland habitats, 2. Re-introduce razorback sucker in the Gunnison River that would result in 10 adult fish per river mile in suitable habitat with a target of re-establishing a population of about 6