9614

• UCREFRP Catalog Number: 9614
• Author: Bowen, Z. H. and e. al.
• Title: Habitat Measurement and Modeling in the Green and Yampa Rivers.
• USFW Year: 2001.
• USFW - Doc Type: \
• Copyright Material: NO

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hydrology, temperature and the distribution of depths and velocities) over one snowmelt
runoff hydrograph at sites used by razorback sucker in the Green and Yampa Rivers; and
(3) document movement and habitat use by adult razorback sucker in relation to patterns
in flow and habitat availability over time in the Green River. This study plan addresses a
National Park Service, Natural Resources Program for Parks (NRPP) Project Statement
titled Impact of Altered Green River Flow on Sediment Deposition and Spawning
Behavior of the razorback sucker (Xyrauchen texanus). This project was ranked by the
National Park Service as a priority project for funding starting in 1998 and continuing
through 2000.
METHODS
Study areas
Two sites were investigated; one on the mainstem Green River and one on the
Yampa River, both in the Dinosaur National Monument near the Utah-Colorado border
(Figure 1). These sites were selected because they represented two of the known
spawning locations for razorback sucker in the Colorado River system, and both had been
surveyed and sampled by previous researchers (e.g., Tyus 1987; Tyus and Karp 1990;
Wick 1997; Modde et al. 1996). The Green River site was located in eastern Utah, about
5.6 km northeast of Jensen, Utah. This site was 1.75 km in length, and located about 4.7
km downstream from the Jensen, UT stream gage. The Green River site (Figure 2) was
dominated by a large island that slit the river into a main channel on the south side of the
island and a smaller side channel to the north. The side channel contained a gravel bar