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A great deal has been learned regarding the razorback suckers that were stocked into Lake Havasu. Undoubtedly, this population represents the most successful reintroduction effort of a riverine population of razorback suckers in the Colorado River basin. Probably our greatest accomplishment was the discovery of a large spawning aggregate located upstream of Needles, California. Several hundred spawners were using this site. Access to these fish will help make monitoring more effective in the future. Our sampling data revealed three trends during the past seven years (1999-2005): 1) The catch per unit effort steadily decreased, 2) the sex ratio of fish sampled has reversed, and 3) the majority of fish captured during this study have come from more recent stockings even though they are fewer in number. These trends reflect a maturing adult community that has established and consolidated spawning activities. The absence of any detectible natural recruitment supports our data; indicating the population is in decline. Population estimate during the past three years suggested razorback suckers numbered 3,570 (CL=1,306-8,925) in 2003, 1,768 (CL=878-3,867) in 2004, and 1,652 fish (CL=706 to 5,164) in 2005. Accuracy of these estimates is hindered by the difficulty of contacting large numbers of fish. This issue should be solved by the discovery of the spawning area. The community also contains over 100 razorback suckers from Lake Mohave that successfully came through Davis Dam Power Plant. Overall survival appears to be roughly 5% for the 31,516 razorbacks stocked into Lake Havasu; however, survival rates appear to be greater for fish stocked further upstream. Calculated survival rates based on the rate of returns varied by location and year ranging from 18 to 76% at Laughlin Lagoon, 12 to 19% at Topock Marsh, 5% at Windsor Beach and no fish were contacted that were released in the lower portion of the reservoir.