9473

• UCREFRP Catalog Number: 9473
• Author: Anderson, R. and G. Stewart.
• Title: Riverine Fish Flows Investigations.
• USFW Year: 2001.
• USFW - Doc Type: Fort Collins.
• Copyright Material: NO

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Dolores River

The headwaters of the Dolores River are in the San Juan Mountains and it flows

mostly northward about 200 miles to its confluence with the Colorado River in Utah. McPhee

dam, which stores water primarily for irrigation, regulates flow for most of its course.

McPhee dam has a capacity of381,000 acre feet and began storing water in 1984. The San

Miguel River is of comparable size and joins the Dolores about 117 miles below McPhee
reservoir and has a relatively unregulated flow.

Access points for boat launches and take-outs were found to be very limited over most

of the river. A suitable site was found in the Big Gypsum Valley, which is 14 miles down

river from the Slick Rock Bridge and 34 river miles upstream of the Bedrock boat launch.

The Dolores River guide (DeVries and Maurer 1977) starts with River Mile (RM) 0.0 at the

Bradfield Bridge and the confluence of the Dolores with the Colorado River is RM 171. This

study used the river guide in reverse RM order to identify landmarks. Beginning at the

confluence as River Mile 0.0, the Utah-Colorado State line is RM 22.4, and the Big Gypsum

Study Site is RM 108.2 to 109.9. The study site starts at the BLM Gypsum Valley

Recreation site and ends about 1.6 miles downstream at the 20R (county road) bridge

crossing. The study station is about 70 river miles downstream of McPhee Reservoir. A site

map and a summary of flows will be presented in the next progress report.

METHODS

Fish Samples

Fish were electro-shocked and netted from an Achilles raft using a Smith-Root electro-

fisher powered by a 5000-watt generator with the anode mounted on a forward boom. The

boat was maneuvered by either oars or by a battery powered 40 pound trolling motor. Two