Correspondences Concerning Upper Colorado Biological Opinions 1993

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Elizabeth Estill, Regional Forester 14 Razorback Sucker Activitv in the 15 -mile Reach Osmundson and Kaeding (1989) found that 76 percent of the razorback suckers captured between 1979 and 1985 were captured in the Grand Valley area. Results of surveys conducted during May and June of 1986 -1988 indicate that areas within the 15 -mile reach may be concentration points for the razorback sucker during spring runoff. Male and female razorback suckers in spawning condition have been found in the 15 -mile reach, although no larvae or juveniles have been found. Although data is limited, Osmundson and Kaeding (1989) think razorback suckers may move into the 15 -mile reach to spawn in the spring, and some individuals may move into lower reaches during the remainder of the year. The current range of the razorback sucker in the Colorado River extends upstream to Rifle, Colorado. Most razorback suckers captured in the Grand Valley area have been located in flooded gravel -pit ponds adjacent to the river. However, Osmundson and Kaeding (1989) documented razorback sucker movement in various river habitats in the Grand Valley area. They documented razorback suckers at river mile 183.6 and at several other locations downstream. Humpback Chub Humpback chub generally do not make migrational movements in the upper Colorado River and tend to reside throughout the year within a limited reach of river. Humpback chub are found inhabiting narrow, deep canyon areas and are relatively restricted in distribution. They seldom leave their canyon habitat (U.S. Fish and Wildlife Service 1982). While humpback chub are regularly found dispersed in the Green and Yampa Rivers, the only major populations of humpback chub known to exist in the Upper Basin are located in Black Rocks and Westwater Canyons on the Colorado River. Critical Habitat Critical habitat has been proposed within the humpback chub's historical range in the following sections of the Upper Basin (58 F.R. 6578). Colorado, Moffat County. The Yampa River from the boundary of Dinosaur National Monument in T. 6 N., R. 99 W., section 27 (6th Principal Meridian) to the confluence with the Green River in T. 7 N., R. 103 W., section 28 (6th Principal Meridian). Utah, Uintah County: and Colorado, Moffat County. The Green River from the confluence with the Yampa River in T. 7 N., R. 103 W., section 28 (6th Principal Meridian) to the southern boundary of Dinosaur National Monument in T. 6 N., R. 24 E., section 30 (Salt Lake Meridian). Utah, Uintah and Grand Counties. The Green River (Desolation and Gray Canyons) from Sumners Amphitheater (river mile 85) in T. 12 S., R. 18 E., section 5 (Salt Lake Meridian) to Swasey's Rapid (river mile 12) in T. 20 S., R. 16 E., section 3 (Salt Lake Meridian).