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19 January mid-winter counts. Numbers of wintering eagles fluctuate from year to year depending on weather patterns. AREA OF IMPACT AND CONCERN FOR ENDANGERED FISHES The San Juan River originates in the mountains of southwestern Colorado and flows southwesterly into the Navajo Reservoir situated on the Colorado/New Mexico border (Figure 2). Downstream of the Navajo Dam, the San Juan River continues westerly, flowing through the towns of Archuleta, Blanco, Bloomfield, Farmington, Fruitland, and Shiprock, New Mexico. It then turns north and eventually reenters the extreme southwest corner of Colorado near Four Corners. Downstream of Four Corners, the San Juan River enters Utah and continues northwesterly through the towns of Aneth, Montezuma Creek, Bluff, and Mexican Hat, Utah, and empties into Lake Powell near Piute Farms Wash. The reach of currently known occupied habitat extends from lake Powell upstream to-approximately river mile 158.6. A diversion structure near Fruitland, New Mexico (the Hogback at river mile 158.6), and a weir at river mile 166.1 span the entire river channel and are believed to be effective blocks to upstream fish migrations (Platania 1990). Ryden and Pfeifer (1995a) reported an observation of a Colorado squawfish 0.2 river miles below the Hogback diversion in 1994, this is the farthest upstream report of a Colorado squawfish during recent studies. A new waterfall (25-30 feet high) developed in 1989 at the lake Powell inflow area during declining reservoir levels and changing river channel alignment between Clay Hills and Piute Farms. This is considered a complete barrier to upstream fish passage when Lake Powell reservoir levels are low, however, in 1995 reservoir levels increased significantly and inundated the waterfall. The status of the waterfall will not be known until reservoir levels recede. The Animas River, from which a majority of Project water will be diverted, is the largest perennial tributary to the San Juan River and affects the entire length of Colorado squawfish and razorback sucker critical habitat. Historically, flows in the San Juan River prior to the Navajo Dam were highly variable. The change in flows at three locations in the San Juan River are listed in Table 1. Table 1 Change in Mean Monthly Flow After the Navajo Dam Units = cfs Pre-Navajo Post-Navajo Percent Change Low Hiah low Hiah low Hiah Farmington 170 13,471 418 9,803 +145% -27% Shiprock 44 19,790 213 9,045 +384% -54% Bluff 65 15,380 250 10,334 +284% -48%