7823

• UCREFRP Catalog Number: 7823
• Author: Miller, W. H., et al.
• Title: Colorado River Fishery Project, Part II, Final Report, Field Investigations.
• USFW Year: 1982.
• USFW - Doc Type: \
• Copyright Material: NO

•
INTRODUCTION
General
The Vernal field station was staffed May 1979. Field sampling
of approximately 300 miles (480 kilometers) of the Green River began in
July. Field work was divided into a standardized sampling program and a
special investigations program. The standardized program characterized
fishery habitat and species distribution; the special investigations
program provided in-depth studies of life history requirements of rare
and endangered fishes. It is important to note that collections utilized
different methods between seasons and locations. Different collections
are cited when data are reported.
Two other studies (White and Yampa Rivers investigations) conducted
by the Vernal station are not included in this report. These two
studies included work in the upper Green River Basin and provided other
information directly related to this study. For a holistic understanding
of the Green River ecosystem, these other studies should be considered
with this study. The White River study (funded largely by the Bureau
of Land Management) and the Yampa River study (funded by Congress,
the National Park Service, and the Fish and Wildlife Service) will be
• available February 1982.
Setting
The Colorado River Basin is separated into upper and lower basins
near Lee's Ferry, Arizona. The upper basin is further subdivided into
its three major river systems, or hydrologic subbasins; Green, upper
main stem, and San Juan-Colorado (Figure 0.
The Green River subbasin comprises about 45,000 square miles
(116,000 square kilometers) of the 109,500 square miles (284,000 square
kilometers) occupied by the Upper Colorado River Basin. The Green River
is the largest tributary to the Colorado River and extends about 500
linear miles (800 kilometers) to its source, the Wind River Range in
western Wyoming.
The study area extends from Split Mountain, the lower boundary
of Dinosaur National Monument, to the confluence of the Green and Colo-
rado Rivers in Canyonlands National Park. The Yampa River, the major
tributary to the Green, enters the Green in the monument. The Green
River above the mouth of the Yampa River is strongly influenced by
releases from Flaming Gorge Dam, constructed in 1963.
The Green River flows through different geologic formations and
• has several tributaries as it proceeds to its mouth. Leaving Dinosaur
National Monument, the Green River flows into the Uinta Basin, an open