7202

• UCREFRP Catalog Number: 7202
• Author: Osmundson, D. B. and L. R. Kaeding.
• Title: Studies of Colorado Squawfish and Razorback Sucker Use of the '15-Mile Reach' of the Upper Colorado River as Part of Conservation Measures for the Green Mountain and Ruedi Reservoir Water Sales
• USFW Year: 1989.
• USFW - Doc Type: Final Report.
• Copyright Material: NO

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Table 1. Numbers of adult Colorado squawfish caught from the upper Colo-
rado River during standardized surveys, 1979-81. Fish were caught from
seven of eleven reaches sampled between Lake Powell, Utah, and Rifle,
Colorado, during pre-runoff, runoff and post-runoff periods.
Miles
------ ----------- Number
Reach Number Percent caught No./mile
Spanish Bottom - Potash 50 26.6 4 0.08
Potash - Big Bend 24 12.8 3 0.13
Big Bend - Onion Creek 15 8.0 2 0.13
Onion Creek - Agate Wash 25 13.3 5 0.20
Agate Wash - Westwater 14 7.4 1 0.07
Westwater - Loma 29 15.4 4 0.14
Loma - Palisade 31 16.5 3 0.10
Total 188 100.0 22
Mean 3.1 0.12
SD 1.3 0.04
Although razorback sucker are very rare in the upper Colorado River, most
of those captured in recent years were found in the Grand Valley area.
During 1979-85, river-wide surveys conducted by CRFP yielded 70 different
individuals; 53 (76%) of these were captured from the Grand Valley area.
Within the Grand Valley, endangered fish utilize three adjacent river
reaches: the 15-mile reach, the 18-mile reach of the Colorado immediately
downstream, and the lower 2.2 miles of the Gunnison River between the
Redlands Diversion dam and the confluence with the Colorado (Fig. 1).
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