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beak <br />2.0 STUDY AREA <br />• The Hawk's Nest Mine permit area lies along the North Fork Gunnison River <br />between Paonia Reservoir about two miles upstream, and Somerset, Colorado, <br />about two miles downstream (Figure 2.0-1 ). The North Fork subdrainage ranges in <br />elevation from 5,500 to 12,000 feet and drains a total of 1,253 square miles, <br />producing an average annual discharge of 469,300 acre feet, or 648 cubic feet <br />per second (cfs) (USGS 1974). The average annual flow rate of the river at <br />Somerset is 315,100 acre feet, or 435 cfs. Flows are generally in a westerly <br />direction into the Gunnison River and, subsequently into the Colorado River. <br />Peak flows occur in May as a result of melting snowpacks. Annual temperature <br />extremes rarely exceed 15°C. <br />Sampling was conducted at five locations on the North Fork Gunnison River; <br />Station C, near the upstream boundary of the permit area: Station D, immediately <br />• downstream from the residential site and adjacent to the East Mine portals and <br />preparation plant; Station E, adjacent to the 4Jest Mine portals and sediment <br />pond; Station F, at the downstream boundary of the permit area; and Station X, <br />upstream from Station E, which was added to further diversify sampled fish <br />habitats. These sites were selected to obtain data and document existing envi- <br />ronmental conditions in the waters flowing adjacent to mining activities, and <br />to provide a basis for comparing waters entering, flowing through, and exiting <br />the permit area. In addition, three sites upstream of the permit area, two on <br />Anthracite Creek (Stations A and B) and one on Muddy Creek (outflow from Paonia <br />Reservoir), were sampled for selected water quality parameters (temperature, <br />dissolved oxygen, conductivity, and pH) and incidental observations noted <br />(Figure 2.0-1). <br />• <br />2-1 <br />