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monthly intervals both from fixed-wing aircraft and boats or rafts. During 1994, radio signals were difficult to detect from the water surface elevation, and most observations were detected from fixed-wing aircraft. Additional effort was made during the spring months to determine factors influencing fish movement to spawning locations. The Escalante spawning area was surveyed twice from ground elevation and three times by fixed-wing aircraft to determine the onset of fish presence at spawning locations in 1994. The same spawning site was surveyed during six consecutive weeks in 1995 to determine dates razorback sucker occupied the spawning areas. Water-discharge and temperature data from the Green River were collected from the U.S.G.S. gage near Jensen, Utah. Macrohabitat data, as defined by USFWS (1989), during the spring and summer months were collected from radio implanted razorback sucker in 1993. An additional habitat type, eddy fence, was added to describe the transition area between an eddy and higher velocity habitat (Le. run, rapid, or riffle). Fish were located both by surface- loop antennas and submersed antennas connected to A TS scanning receivers. Macrohabitat, depth and substrate data were collected to characterize the locations used by the study fish. In an effort to determine habitat use by subadults in a wetland, radio transmitters were implanted into five age-2 captive reared razorback sucker stocked into Old Charley Wash. These fish, 178-279 mm in total length (mean = 229 mm), were PIT tagged and implanted with 4.5 g, AVM, internal-antenna radio transmitters. Fish were implanted on June 29, 1993, and released into Old Charley Wash the following day. Attempts were made to locate fish at approximately four-week intervals. Location in the wetland, depth and cover/vegetation type were recorded during each contact with individual fish. RESULTS Movement patterns based on tag recapture data Adult razorback sucker capture data included 771 observations. All fish were collected between river kilometers 80 and 564, with only 20 observations occurring below river kilometer 370. Pooled observations of fish among years, above river kilometer 370, showed a distinct distribution pattern during the spring months. Of the ten fish captured in early April, nine were captured near the mouth of the Duchesne River, RK 399 (Figure 3). In mid to late April and early May, 73% of the fish were collected between river kilometers 491 and 507, the spawning area most often used by razorback sucker. Only 4% of the fish were collected at the spawning site in the lower Yampa River. Between one and approximately 40 fish were found each month between the mouth of the Duchesne River and the outlet to Old Charley Wash. Following spawning (after mid May), 62% of the fish captured were downstream of the primary spawning bar (RK 501). Following mid-May, many fish were captured at the mouths of tributaries including 85 fish at the mouths of Ashley Creek (RK 481) and 13