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and White rivers), and in Grand Junction, Colorado (Colorado and Gunnison rivers). Water Discharge on Photograph Dates Aerial photographs were taken in May 1993, 3 days before peak flow in the Green River and 2 days after peak flow in the Yampa and White rivers (Figure 3). Photographs were taken on the lowest flow day in September in the Green River and about 3 weeks after low flow in the Yampa and White rivers. Aerial photographs were taken in June 1993, 13 days after peak flow in the Colorado River and 23 days after peak flow in the Gunnison River (Figure 3). Photographs were taken on the lowest flow day in September in the Gunnison River and about three weeks after low flow in the Colorado River. Distribution of Bottomland Habitats Green River. There were 132 bottomland habitat sites with a potential (historical) of 18,430 acres (7,459 ha) along the Green River (rm 0-393 [rkm 0-632]) in 1993 (Appendix D; Table D.1.). Of this total, 7,720 acres (3,124 ha; 74 sites) were inundated during the May high-water flow period and 2,438 acres (987 ha; 28 sites) in the September low-water flow period. The largest flooded bottomland areas (Figure 4) were located in the Browns Park National Wildlife Refuge reach (rm 368-393 [rkm 592-633]; 1,371 acres [555 ha]) and between Pariette Draw and the Escalante Ranch (rm 238-310 [rkm 383-499]; 6,093 acres [2,466 ha]). The greatest concentration of flooded bottomland sites were within the Ouray National Wildlife Refuge (rm 249-265 [rkm 401-427]; 2,265 acres [917 ha]). Only 16% (12 sites) of the 74 sites flooded in May had a hydrological connection to the river, whereas 89% (24 sites) of the 28 sites that were wetted in September were still connected to the river (Appendix E; Tables E.1 and E.2). The majority of these sites had only one connection to the river. Sixteen percent (12 sites) of the May flooded sites received some water from gravity fed (irrigation) water sources and 840 (62 sites) received water from groundwater sources. Of the 132 potential bottomland sites, 4% (6 sites) had natural levees between them and the river, whereas 11% (15 sites) had human-made levees or berms. Over 70% (93 sites) had emergent vegetation in May. There were 30 floodplain depression bottomland habitat types and 99 floodplain terrace habitat types along the Green River. The remaining flooded habitat types consisted of two flooded gravel pits and one flooded river confluence. Yampa River. Only 22 acres (9 ha; 1 site) of bottomland habitat were available in the Yampa River just upstream of the Yampa and Snake river confluence (rm 48 [rkm 77]) in 1993 (Appendix D; Table D.1.). It was flooded during the May high-water period, but dry in the September low-flow period 15