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9 At Green River, Utah, the mean annual suspended sand load is about 6 percent greater than the load computed for the site below Willow Creek. The inter- vening tributary in this reach, the Price River, is gauged near Woodside, Utah, about 22 miles upstream of its confluence with the Green. Inadequate gauge records prohibit the calculation of its average annual sand-load contribution to the Green. However, since the mean annual discharge of the Price is only 2 percent of the flow of the Green, the sand load contributed by the Price is not likely to be a major component of the total sand-load of the Green. The similarity of the mean annual sand-load estimates of the Green near Willow Creek and at Green River, Utah, suggests that quasi-equilibrium in terms of sediment transport exists for this reach. On average for 1965-1987, the suspended sand load of the Green near the Dinosaur Quarry is nearly 50 percent of the river's sand load at Green River, Utah. About two-thirds of this difference, 1,066,000 tons/year, is accounted for by the White and Duchesne. Ephemeral washes and other tributaries do contribute sediment to the Green, but most of this sediment is much finer than the bed- material size range of the Green. The mass balance of sand loads calculated from the long-term gauge histories of the Green, indicates that presently, the Green is in quasi-equilibrium from the Dinosaur Quarry to Green River, Utah, transporting just the sand load that is delivered to it throughout this reach. SEDIMENT TRANSPORT AND CHANNEL GEOMETY INTERACTIONS Channel dimensions are integrated results of all water and sediment discharges conveyed by a channel. Schumm [8], [9] provided two general relationships which indicate channel responses to changes in water and bed-material discharge: Qw = b,a,d s Qs = b,)L,s d,p where: Qw mean annual discharge or mean annual flood Qs bed-material transport b. channel width ?- Y A channel wavelength d channel depth s channel gradient p sinuousity An increase in Qw or Qs, either individually or in unison, should cause an increase in channel width. A decrease in channel width could result from a decrease in either or both Qw, and Qs. Changes in channel width were measured from aerial photography in this study and channel depth data were available for one location during the time span that included construction and operation of Flaming Gorge. Channel wavelength, channel gradient, and sinuousity changes were not measured in this study.