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Although some natural recruitment is occurring based on the capture of razorback suckers 480 mm TL or smaller, the present natural recruitment is considered inadequate to maintain a self-sustaining population indefinitely. After considerable discussion, the Biology Committee recommended that the Middle Green River razorback sucker stock be increased by 500 fish to 1,000 adults. This stocking plan outlines the approach that will be used to assist in accomplishing this goal during 1996 and 1997. III. BACKGROUND The largest concentration of spawning razorback suckers in the Upper Colorado River Basin occurs in the Middle Green River between RK 486.4 and RK 504.0 at a site known as "Razorback Bar" (RK 311.5) when the water temperature averaged 14.1 C with a range of 9 to 17 C (Tyus and Karp 1990). Most ripe razorback suckers (98%, n = 191) were collected in flowing water of riffles but, during the high flows of 1986, 30% of ripe or tuberculated fish were captured in the flooded river bottoms of Old Charley Wash and Stewart Lake Drain (Tyus and Karp 1991). Twelve ripe razorback suckers were captured in Old Charlie Wash (an off-channel lake with an inlet and an outlet) in late May and June (Tyus and Karp 1990). These fish were in excellent condition suggesting that the fish may use such sites after spawning to forage on abundant zooplankton as a mechanism for restoring their condition following post-spawning. These razorback suckers exhibited a high spawning fidelity to a specific riffle (Tyus and Karp 1990) and the phenomenon of imprinting by razorbacks is presently under study (Scholz et al. 1993). Twenty-six razorback suckers (22 males and 4 females) in breeding condition were recaptured in the same spawning reach in different years, indicating a strong fidelity to that site (Tyus and Karp 1990). Tyus and Karp reported that six of the fish were captured at that site in three different years. McAda and Wydoski (1980) reported capturing 14 ripe razorback suckers (12 males and 2 females) on a bar composed of cobble (20 to 50 mm in diameter) that was located about 400 meters upstream from. the mouth of the Yampa River during May of 1975. Other females that were captured nearby in the Green River and Yampa River were not ripe, suggesting that females do not occupy spawning areas until they are ready to spawn. Thirty-two ripe razorback suckers were captured from the lower Yampa River during the spring of 1975, 1981, 1988, and 1989 (Tyus and Karp 1989). The average depth at the capture site was 0.61 m and the average water velocity was 0.64 m/s. The average water temperature was 13.8 C with a range of 10.5 to 16 C (Tyus and Karp 1990). Tyus and Karp reported a capture of a ripe male in the lower Yampa River in 1988 that had been tagged at the same site in 1981 indicating a fidelity to this spawning site. Although razorback sucker spawn in the Middle Green River and produce numerous larvae, low survival during the early life stages results in poor recruitment. Poor survival is attributed, in part, to predation and competition from nonnative fishes and starvation. Present nursery areas consist of backwaters along the main channels that are dominated by nonnative fish species. Zooplankton production in the main channels is extremely low in the upper 2