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in the Green River during the second sampling period. Occasionally, two additional nets were set in the raceway upstream from the pumping station and power plant (Figure 2), and nets were set every six hours on August 2-5. All nets were equipped with mechanical flow meters (General Oceanics, Inc.). When the measured water velocity seemed abnormally low, an estimated velocity based on readings from other meters was used rather than the actual data. Working conditions in the raceway upstream from the pumping plant and power plant were dangerous, due to the depth and velocity of the water, so nets were not set at this site very frequently; no fish were found in the samples from this additional site, so these data were excluded from data analysis. Nets were usually set at about 0700 each morning and allowed to fish for about two hours. However, many nets were deployed for shorter periods of time (especially in May) due to large amounts of debris that was suspended in the water on some occasions. Debris collected in the nets was preserved in alcohol and taken to a laboratory, where fish were removed. All larval fish collected were sent to the Larval Fish Laboratory in Fort Collins, Colorado, for identification. Subadult and Adult Entrainment The gates of the Green River Canal were closed on the evening of August 5, 1998 and sluice gates were opened to remove a large tree that had lodged in an overflow structure. The tree was removed on the morning of August 6, 1998; the gates were returned to their original positions and the canal was filled with water again at that time. While the canal was dry on the morning of August 6, I visually searched for stranded fish in approximately 0.25 miles of the canal near the gates and two miles of the canal through the town of Green River, Utah. The Green River Canal was shut off for the winter on November 27, 1998, but I was not notified until November 30, 1998. On that morning, I searched for stranded fish in approximately two miles of the Green River Canal and 1 mile of a smaller irrigation-drainage canal running through Green River, Utah. The raceway gates were closed in February 1999 to allow the Green River Canal Company to build a concrete wall in front of the intake to the Thayn Power Plant. The purpose of the wall was to increase the volume of water delivered to the Green River Canal. This, in turn, reduced the volume of water delivered to the power plant. The wall caused high water velocities to form in front of a grate that is used to keep debris from entering the power plant. Water velocities between the wall and the grate were increased and were high enough to cause large fish to become impinged on the grate. One of the turbines in the power plant was shut off on May 20, 1999, which reduced the water velocity in front of the grate enough to keep most fish from becoming impinged. In addition, the wall in front of the power plant intake was removed on June 30, 1999, which further reduced water velocities in front of the grate. During the period from May 4 through May 24, 1999, fish caught on the screen were removed and identified by Kim Olsen, a Utah Division of Wildlife Resources conservation officer, and Lee Thayn, co- owner of the power plant. Neither of these individuals have any training in ichthyology, so not all of the collected fish were identified to species. 3