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Final Report 3-46 September 2000 identified by these authors, who used historic aerial photography and measurements of channel shape over a 30-year span after closure of Flaming Gorge Dam. Stage 1 (channel narrowing and development of banks) is similar to the degradation conditions described for Reach 1 by Andrews (1986). Stage 2 (channel widening, subaqueous bar formation, braided channel) was observed from a study of aerial photography from 1977, 1984, and 1994. Stage 3 (bar stabilization, fluvial marsh development, and continued channel widening) has been observed since 1994. Merritt and Cooper (1998) projected that channel widening in Browns Park could continue for several decades but that coalescence of islands will lead to formation of a smaller meandering channel over a longer time span. Grams and Schmidt (1999), in addition to providing a description of the geomorphic characteristics of Reach 1 and portions of Reach 2, developed estimates of pertinent sediment-transport parameters for a range of channel conditions. Their estimates of average boundary shear stress during floods and critical shear stress of gravel bars show that the channel gradient and bar-material size in both the canyon and meandering portions of Reach 1 are in approximate adjustment with pre-Flaming Gorge Dam flood conditions. Although the river flows alternately through sections of extremely different geomorphic character, a near-equilibrium condition, where river morphology is adjusted to sediment and water inflow, exists throughout Reach 1. Martin et al. (1998) described the redistribution of sand in Lodore Canyon during a 3-year study (1995 to 1997) of this portion of Reach 1. During their study, two periods of releases greater than power plant capacity (130 m3/s) occurred - a 3-day event that reached a peak of 187 m3/s on May 30, 1997, and a 6-day event that reached a peak of 244 m3/s on June 17, 1997. Measurements indicated that sediment transport at 244 m3/s was more than 3 times higher than transport at 130 m3/s. The magnitude of scour and fill observed after these high flows was large relative to the topographic change that occurred, which indicated significant redistribution of sand. More deposition and erosion occurred during the 244-m3/s event than during the 187-m3/s event. The net effect of the two high releases was significant erosion on the offshore portions of eddy sandbars and significant deposition on the onshore portions of sandbars at the stage of 130 m3/s and higher flows. The initial peak of 187 m3/s caused net offshore deposition, but the second peak of 244 m3/s caused net offshore erosion. Aerial photographs confirmed that net deposition of sand occurred at higher elevations and that the long-term trend of channel narrowing and vegetation encroachment of low-elevation deposits had somewhat reversed. Orchard and Schmidt (2000) determined that the active channel through Desolation and Gray Canyons decreased an average of 19% since the beginning of the century. They identified two episodes of channel narrowing as evidenced by two new surfaces along the channel. The cottonwood terrace is an abandoned floodplain that began to stabilize between 1922 and 1936 as a result of drier weather conditions. After closure of Flaming Gorge Dam, a second lower surface has become densely colonized by riparian vegetation and is accumulating sediment through vertical accretion. This process is continuing and appears to be contributing to the loss of in-channel fish habitat.