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?'9 waters into -theme Green River. These were Red Creek (11.2 ML: Nexmt.= lion Creek (43.6 MBD), and the Yampa River (65.8 MBD). Turbidity readings at Little Hole were less than 25 JTU (Jackson Turbidity Units) with'the exception of the morning of June 11, 1965 when a sudden in- crease in flow caused temporary scouring of the riverbed and turbidity increased to 62 JTU. Turbidity at Carr Ranch did not exceed 700 JTU during the'-stddyr; 'but' tile` maximum observed at Echo Park and Island Park was 5000 JTU (Table 4). Mean concentration of suspended sedi- ments at Jensen was 1529 ppm before impoundment and 925 ppm after (Table 5). Dissolved 0 en is Dissolved oxygen concentrations were always 6.0 ppm or above (Table 6). They were highest at Little Hole and decreased sharply between Little Hole and Carr Ranch. Dissolved oxygen concentrations at Echo and Island Parks were similar during the summer months. The few mea- surements made during the winter months did not contradict the above generalizations. Dissolved oxygen concentrations at Little Hole fluct- uated as much as 3-4 ppm over a 24-hour period. Saturation (100 per- cent) was often reached after noon. Daily fluctuations decreased with increasing distance from the dam, and this was probably a reflection of of reduced algal growths downstream. At Island Park the maximum fluctuation observed in a 24-hour period was 0.8 ppm. Before construction of the dam some concern was expressed that • water drawn from the hypolimnion during summer months might be devoid of oxygen. This situation occurred in August, 1964, when water contain- ing less than 1.0 ppm dissolved oxygen was released. Oxygen content