7147

• UCREFRP Catalog Number: 7147
• Author: Holden, P. B. and C. B. Stalnaker
• Title: Distribution and Abundance of Mainstream Fishes of the Middle and Upper Colorado River Basins, 1967-1973
• USFW Year: 1975
• USFW - Doc Type: Transactions of the American Fisheries Society
• Copyright Material: YES

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HOLDEN AND STALNAKER-COLORADO RIVER FISHES

219

Many of the streams in the upper basin
flow free, but two major reservoirs were
built in the 1960's: Baming Gorge Reser-
voir located on the upper Green River and
Lake Powell just upriver from Marble and
Grand Canyons (Fig. 1).
Evermann and Rutter (1895) summarized
collections from the Colorado River made
prior to 1894. Taba, Murphy, and Frost
(1965) made collections in the Colorado
River for several miles below Moab, Utah,
and Smith (1959) and McDonald and Dot-
son (1960) conducted preimpoundment sur-
veys in Glen Canyon. A fish eradication
program in September 1962 (Binns et al.
1964) effectively eliminated most native
species above and for many kilometers
below Flaming Gorge Dam before closure
in November 1962. Vanicek, Kramer, and
Franklin (1970) documented the distribution
of native fishes below this dam following
closure, and summarized preimpoundment
surveys. They found no reproduction of na-
tive fishes in the cold tail waters of the
reservoir for 104 kilometers downstream.
At that point, the Yampa River joins the
Green and ameliorates the coldness of the
Green somewhat. Areas noi previously
studied include the lower 400 km of the
Green River, the Yampa River, and the
Colorado River above Moab, Utah.
Minckley and Deacon (1968) reported
two squawfish taken in the Grand Canyon
in the mid 1960's. No subsequent accounts
of squawfish from this canyon have been
published. Minckley (1973) reported the
humpback sucker as nearing extinction
helow Lake Mohave.
Presently, Colorado squawfish and
humpback chub are considered "En-
dangered" by the U.S. Department of the
Interior (1973). Humpback sucker and
bony tail chub are also rare (Miller 1972).
The present study was undertaken to de-
termine the status of fishes in the middle
and upper Colorado River basins, with
special emphasis on endemic, large-river
forms.
The objectives were: (1) to determine
distribution and relative abundance of
fishes in the Colorado River basin above

Lake Mead, and (2) to identify areas im-
portant for reproduction of endangered
forms.

STUDY AREA

That part of the Colorado River basin
(Fig. 1) considered in this study includes
the Green River system from Craig, Col-
orado; the Yampa River to the junction of
the Green and Colorado Rivers; and the
Colorado River from Hifle, Colorado to
Lake Mead, excluding Lake Powell. Sev-
eral larger tributaries also included were
the Gunnison River below Delta, Colorado,
and the Dolores, Price, Whitc, and Little
Snake Rivers.
The main system was divided into 12
sampling areas:
1. The Upper Yampa River from Craig,
Colorado, to Juniper Springs, Colorado,
approximately 80 km.
2. The Lower Yampa Hiver in Yampa
Canyon, Dinosaur National Monument, ap-
proximately 72 km.
3. The Green River from the mouth of
the Yampa River to the south boundary of
Dinosaur National Monument, about 32
km.
4. The Green River from Ouray to
Green River, Utah, including Desolalion
and Grey Canyons, about 192 km.
5. The Green River from Mineral Bot-
tom to its mouth, most of which is in
Canyonlands National Park, about 104 km.
6. The Colorado River for 16 km up-
stream from mouth of the Green River.
7. The Colorado River upstream from
Moab, Utah, approximately 32 km.
8. The Colorado River from Grand Junc-
tion to Fruita, Colorado, about 16 km.
9. The Colorado River near Rifle, Col-
orado.
10. The Gunnison River below Delta,
Colorado, .to its mouth.
11. The Colorado )livcr in Glen Canyon,
immediately below Glen Canyon Dam.
12. The Colorado Hiver in Marble and
Grand Canyons, Arizona.
Most of thc study area consists of can-
yons; however, major differences exist in
fish habitat. Areas 5, 6, and the upper

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