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10 I I I I I I I I I I I I I I I I I I I Table 2. Mean monthly and monthly minimum flows recorded at the Palisade gage, IS-Mile Reach, Colorado River for summer months during the three years of the study. Year July August September October ( cfs ) (cfs) (efs) ( efs ) 1999 Mean 4,721 2,221 1,752 1,837 Minimum 2,500 1,380 1,180 1,430 2000 Mean 1,271 913 986 916 Minimum 648 581 665 543 2001 Mean 995 1,133 1,014 809 Minimum 477 686 754 535 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 acres/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 Guidebook (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 put together and presented in the next report.