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<br />1 <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />i <br />capture compared to flow and temperature regimes gathered from U.S. Geological Survey gauges <br />or other sources (pers. comm., G. Smith, U.S. Fish and Wildlife Service, Denver, CO). <br />Temperature data were average daily or instantaneous readings. Winter and early spring <br />temperatures (through mid-April) for the middle Green River gauge at Jensen, Utah were not <br />available in 1998 and 1999 but were estimated from the average of daily readings collected from <br />1980 to 1997. Lower Green River data were from the gauge at Green River, Utah. <br />RESULTS <br />Razorback sucker distribution.-Since 1992, wild adult razorback suckers were captured <br />throughout most segments of the Green River Basin, including the lower and middle Green <br />River, at the confluence of the San Rafael River, in the lower Yampa River, and in the Green <br />River in Lodore Canyon. We used distributional data collected only since 1992 because other <br />investigators had reported data collected prior to then (Modde et al. 1996). During 1996 to 1999 <br />Basinwide and other sampling, most effort and captures (97%, N = 118 unique fish) were <br />concentrated in the middle Green River from upstream of the White River to just below Split <br />Mountain Canyon (Fig. 2). Most fish captured in the middle Green River were from the <br />Escalante reach (4b %), whereas fewer were captured in the Ouray (32 %) and Jensen (22 %) <br />reaches. Most razorback suckers (70 %) captured in the middle Green River from 1996 to 1999 <br />were from just three locations, the Escalante Ranch spawning sites (RK 500.4), Ashley Creek <br />(RK 481), and near Old Charlie Wash (RK 401.4 to 401.6). Most adult razorback suckers were <br />captured in May (56 %) or June (37 %). Adult razorback suckers were very rare in other portions <br />of the Green River Basin. Only two adults were taken in each of the lower Yampa (RK 0.0 to <br />11 <br /> <br />