9347

• UCREFRP Catalog Number: 9347
• Author: Neuhold, J. M. and T. C. Annear.
• Title: An Ecological Characterization of the Yampa and Green River in Dinosaur National Monument.
• USFW Year: 1981.
• USFW - Doc Type: Logan, UT.
• Copyright Material: NO

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Monument. Much of this sparsely populated region is used for agri-
cultural purposes, and dewatering of the river for irrigation consti-
tutes the most important development of the aquatic resource. The
greatest impact of dewatering on Yampa River ecosystems is likely felt
only during late summer months when flows are minimal. Maybell,
Colorado, (population 82) located 25 km east of the closest sampling
site, is the nearest population center to the study area.
Within Monument boundaries the topography through which the Yampa
River flows changes drastically as the river plunges through high can-
yon walls to its confluence with the Green River in Echo Park.
The Yampa River normally carries large amounts of suspended
sediment through Dinosaur National Monument. Highest concentrations
are associated with spring runoff, and by late summer, waters are
relatively clear. The mean annual suspended sediment load at Deer-
lodge Park (the Monument's eastern boundary) exceeds 1.7 million tons.
Of this amount, 69 percent originates in the watershed of the Little
Snake River. Notably, the Little Snake contributes only 27 percent
of the annual discharge (Andrews 1978).
Predominant streamside vegetation is composed of Utah juniper
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(Juniperus osteosperma), boxelder (Acer negundo), tamarisk (Tamarix
pentadra), sedges, rushes, and grasses (Holmgren 1962a).
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Using the stream classification system mentioned previously,
the Green River is technically considered a fifth order stream
above its confluence with the Yampa River and a sixth order stream
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