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STUDY SITES Sampling trips were made possible through the generous cooperation of Tom Chart and Melissa Trammel, UDWDNR Moab, who were conducting weekly larval fish sampling with light traps. Trips began at Mineral Bottom, RK 52, withjon boats to access the backwaters. The fish team placed six quadrafoil design light traps in Millard Canyon, and three each at Anderson Bottom and Holeman Canyon. Sampling was performed for two consecutive nights during the twelve hour period from dusk to dawn. Each backwater was divided into front (that portion closest to the main river channel), middle and back thirds, with sampling efforts concentrated in the latter two. Obviously, this changed with increasing river flows, as did depths and dimensions, so that what was initially considered the back one third in the beginning of the study, became the middle third towards the end. Millard Canyon Millard Canyon, located at RK 34 on the lower Green River in Canyonlands National Park, was the most upstream backwater. This was the only site that did not have a point bar formed across its entrance at the start of the field season. It was the largest and longest backwater, approximately 10m wide at the mouth, 150 - 200 m long, with uneven depths up to 4 m. The back portion of the site became estuary-like as river levels increased, with shallow depths and submerged vegetation. In general, the substrate was comprised of coarse red sand and silt with very little clay. Salix sp. grew densely along the sides of the entrance and first one third of the backwater. A large bed of Tvpha lies at the base of a sandstone wall on the south side of the backwater approximately two thirds in, and a mixture of willow and Tamarix fill the shallower, back one third. The USGS 7.5 I HorsethiefQuadrangle map shows a perennial creek draining into the main stem of the river through Millard Canyon, though it was not possible to find it towards the end of the field season. A short hike approximately 800 m up the drainage revealed a dry stream bed suggesting that the stream either submerges or is ephemeral. Anderson Bottom Anderson was the middle backwater site located at RK 31. It was roughly circular and pond-like; approximately 20 m in diameter. Access to the backwater was impossible by boat during the first two weeks of sampling due to a large point bar which extended nearly across the mouth, leaving an entrance of one meter wide. Tamarix, Salix. and a few young Populus trees formed the riparian vegetation. A reed bed grew behind the point bar at the backwater entrance, both of which became submerged with rising water levels. A large, dead cottonwood was submerged 2