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RESULTS AND DISCUSSION Radiotel eme try Green River Radiotelemetry of adult Colorado squawf ish was expanded in the Green River Basin in 1983. A total of 15 adults were implanted with radio- transmitters in the lower Green River (Table 1). In addition, FWS funds were used to implant 14 adults in DNM and the upper Yampa River. Tracking of these fish was very successful and contact made with 28 of the 29 fish in late summer. Even so, adverse flood conditions made it ' d ifficult to locate and follow fish and some were Iost for long periods. Contact was lost with 5 fish during the spawning period in the Yampa River and also with 5 fish in the Green River during this period (July- August). Of the remaining fish, 15 exhibited long distance movement of 80 km (50 mi) or more. The movement patterns of the 15 adults implanted in the lower Green River is given in Figure 2. Past studies have identified two spawning areas in the Green River Basin. Three fish implanted in the lower Green migrated to the Three Fords Rapids area of Gray Canyon at river km (RK) 250 and are believed to have spawned in that location. Although suspected as a spawning site in 1982, not enough Colorado squawf ish were radio-tracked to this area until this year. When 1981-1983 data were combined, a spawning migration pattern similar to that of the Yampa River was illustrated (Figure 3). Eight fish implanted in the FWS study in the Yampa and upper .Green migrated to the lower 32 km (20 mi) of the Yampa Canyon and are believed to have spawned there. The migration observed in 1983 (Figure 3) was almost identical to the pattern observed in 1981 (Figure 5) . No new spawning areas were positively identified in 1983, but some new observations on behavior were made. Two adult Colorado squawf ish (No. 435 and 3073, Figure 2) moved 128 km (80 mi) downstream into Labyrinth Canyon and were both located near RK 64 (RM 40) during August. Although netting produced no ripe fish at that site, it is possible they spawned there. Another fish (No. 3030) moved from Green River, Utah into Cataract Canyon of the Colorado River, where three contacts were made by air in August. It is not known if a spawning area exists at that location, but the habitat appears suitable. Colorado squawf ish were tracked into shallow flooded alfalfa fields in both the-upper Yampa and lower Green rivers during high spring floods, a habitat use not previously observed. Of particular significance is the migration of two adult Colorado squawfish (No. 3037 and 3039; Figure 2) implanted in the lower Green River which successfully swam upstream over the Tusher Wash Diversion Dam (RK 317) to reach the spawning grounds in Gray Canyon. As in 1982, netting was conducted at the two suspected spawning grounds (Figure 6) in an attempt to verify spawning and evaluate movement of fish to them. Netting in the Green River site (Gray Canyon) produced 12 6