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In 1999,15 bonytail, again from the 1996 cohort (average TL 409.7 mm)were implanted with radio transmitters (ATSiIll40 HZ, 6 g., with a 90-day battery life) at Wahweap State Fish Hatchery on March 13 and were stocked into the Colorado River at Dewey Bridge (RM 94.3) on March 24. In addition, two roundtail chubs were radio-tagged after being captured on May 4, 1999 at the confluence of the Dolores River (RM 96.5). The average TL of the radio-tagged bonytail was 389.7 mm, and 342 mm for the roundtails. All tagged fish were tracked daily for the first two weeks after release and then at least twice weekly. A total of 31 general tracking days and two intensive 24-hour tracking periods were completed between April 1 and August 24, 1999. Radio tracking occurred from Dewey Bridge (RM 96.2) to Spanish Bottom (2.5 RM below the confluence of the Green and Colorado rivers). On March 9,2000 a final group of 14 bonytail from the 1996 cohort (average TL 410.7 mm) were implanted with radio transmitters at Wahweap (ATSiIll40 HZ, 6 g., with a 90 day battery life), returned to the growout pond for a week of recuperation, and then stocked into the Green River on March 20. The bonytail were tracked daily for the first two weeks after release and then at least twice weekly. In total, 34 days of general daily tracking occurred between March 21 and July 26,2000. A 24-hour intensive tracking session was completed with one fish. The portion of the river near the release site (RM 120.0) was monitored more frequently than other areas, but the section from Tusher Wash Diversion Dam (RM 128.5) to Mineral Bottom (RM 52.2) was checked on a few occasions, as was the section from Mineral Bottom to the confluence with the Colorado River (RM 0.0). RESULTS AND DISCUSSION Obiective 1: Reintroduction of bony tail into the Colorado River, Professor Valley and in the Green River, near the town of Green River, Utah. Stocking For this study, stocking of hatchery-reared bonytail began in the fall of 1996 in the Colorado River and the fall of 1998 in the Green River and was completed in the fall of2001 on both rivers. During these time periods, 84,603 bonytail were released in the Colorado River and 127,714 were released in the Green River. Fish stocked in the Colorado River ranged in size from 65 to 354 mm during the fust three years (Figure 2). The majority of these fish (82%) were under 140 mm and only 1.6% were over 200 mm. After 1998, only small samples.(100-300) offish were measured and weighed before release. Consequently, only mean TL for each release is reported. Only three releases of cohorts averaging more than 150 mm occurred in the six years of stocking. One small release (104) offish averaging 316.2 mm and two larger releases ofbonytail (average TL 169.0 and 187.4 mm) occurred in the spring and fall of2000 (Table I). 1996 - The first stocking ofbonytail took place on October 18, 1996. Approximately 2,000 age 0 bonytail raised at Wahweap State Fish Hatchery were stocked into the Colorado River at RM 96.2 in a large backwater upstream of Moab, UT (Table 1, Figure 3). AU fish were measured 7