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Adult and iuvenile fish collections A total of 308 adult and juvenile fish were collected during five sampling trips (Table 2). These fish represented nine species and one suspected hybrid. The dominant species collected were roundtail chub (53%), flannelmouth sucker Catostomus latipinnis, (20%), common carp Cyprinus carpio, (11X), and channel catfish Ictalurus punctatus, (9%). Also collected were one Colorado squawfish, seven humpback chub, and two suspected humpback and roundtail chub hybrids. The Colorado squawfish (yellow Carlin tag # 1029) was a radiotagged fish that was captured to check sexual condition. Total length of this fish was 824 mm and no tuberculation or sexual products were evident. The humpback chub ranged from 216 to 320 mm total length. Two humpback chub collected on June 8 were tuberculated; their sizes were 219 and 310 mm total length. Larval fish collections Larval fish were collected on June 28, 1988 to look for evidence of Colorado squawfish reproduction in the lower Little Snake River. Five collections were made in the lower eight miles. Five species were represented in the 1260 larvae (10-30 mm-total length) collected (Table 3). Flannelmouth sucker made up 82% of larvae collected while bluehead sucker Catostomus. discobolus comprised 17%. Other species collected included sand shiner, speckled dace and roundtail chub. Discharge measurements Discharge was measured during baseflow conditions in July and September 1988 (Table 4). On July 27, we measured 10.6 cfs discharge at the USGS gaging station near MCR 10 bridge between 1640 and 1700 hours and 9.8 cfs at RMI 4.5 below the canyon. The USGS gaging station average discharge for that day was 3.8 cfs. On September 29, we measured 10.9 cfs at the gaging station while the USGS station reported 9.9 cfs. At the lower site (RMI 4.5) we measured 8.3 cfs. Habitat changes with varying discharge During the high discharge of spring run-off, wide, low gradient reaches of the river tend to remain homogeneous. Eddys are often formed during this water level, providing habitat diversity for fish use. The river tends to be silt laden and is warmed from flowing over shallow sandy areas. Within the higher gradient of the canyon (RMI 8.0-6.0) deep, turbulent eddys are formed. along canyon walls and behind large boulders. High flows through this constricted canyon tend to cut deep pools necessary for fish survival during low water periods. During low discharge, baseflow periods, the wide, low gradient reaches become almost unusable by most fish. The river tends to braid through the sandy substrate, forming small, shallow channels impassable by most fish. Residual pools are few, often scattered, and usually very shallow. The water is usually very clear during baseflow. Within the canyon (RMI 8.0-6.0) pools tend to be deeper and more common. We noted one pool (RMI 7.4) that was over 10 ft deep when most pools outside the canyon had maximum depths of 3 ft. 5