7804

• UCREFRP Catalog Number: 7804
• Author: Hagan, H. K. and J. E. Banks.
• Title: An Ecological And Limnological Study of the Green River in Dinosaur National Monument.
• USFW Year: 1963.
• USFW - Doc Type: \
• Copyright Material: NO

,.

August 25, 1962
The river lost its red color and decreased in turbidity throughout the
day. It dropped slightly. Returned to the yampa River about dusk to
collect mayflies, but there were none.

General observations at Echo Park
(July 29-AUS. 25, 1962)

Water samPling stations. Water samples and temperatures were taken on
the Green River directly north of the ranger station. Water samples and
temperatures on the Yampa River were taken in two places - in the south
channel of the river, and father upstream before the river split into tuo
channels.

Hater. The color of the water varied on certain ~a. Some days the
water would be a deep red color, and on others, a brown or yellow color.
M:>st ofH the time the water was a very light green color. Turbidity varied
from turbid to very turbid. It could be considered turbid most o'f thet1me.
Chemical analyses were made numerous t1mes on both rivers and at different
times at the day. On the Green River, the pH did not fluctuate from the
7.5 mark. The dissolved oxygen varied from 6.8 - 8.0 p. p. m. phth. varied
from 0 p.p.m. to 10 p.p.m.; M.O. varried from 121 p.p.m. to 151 p.p.m. The
pH on the Yampa river was always 7.5. The dissolved oxygen varied trom
6.0 p.p.m. to 8.1 p.p.m. phth. varied trom 0 p.p.m. to 10 p.p.m. l-LO.
varied from 123 p.p.m. to 141 p.p.m.

Bottom. The bottom type on the Green River in Echo Park is pr1ma.rllY
rubble with some silt and sand mixed into the rubble. The bottom types on
the Yam,pa in this area was predominantly sand with some large rocks and
boulders in places.

Vegetation. Vegetation in the Green River would be considered sparse.
There were small amounts of algae clinging to the rubble in most areas.
Vegetat ion in the Yampa. was somewhat more dense in the Yampa than in the
Green, although it still could be considered sparse. There was enough algae
on the bottom to give the water a green color. Depth of visibility was
between 3 and 4 feet.

Temperature. The water temperature on both rivers changed according
to weather conditions. Dur1nga.24-hour period!, the water temperature
changed from a low of 65.00F. to a high of 72.0 F. The highest water
tempera.ture that I recorded on the Green River was 720-,. The highest
temperature that I recorded on the Yampa River was 74. OF. The Green usually
ran several degrees cooler than the Yampa River, sometimes a difference in
temperature of 4 or 5~. was observed.

Shore. Deep canyon areas on all sides. The shoreline on the upper
end of the study area consisted of sandbar, ",hile the lower portion of the
study area consisted of rather high banks with trees (mostly l3oxelder) and
other vegetation along them.

Current. 'I'he current in the Green River in this area could be considered
as changing from rapid at the upper end of the area to moderate at the lower
end. The current in the Yampa was SlO'I.

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