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West Elk Mine . the East Fork as it is being filled. Reservoir releases regulate stream flow during late summer. Minnesota (Monument) Reservoir effectively regulates spring runoff from Dry Fork with reservoir releases controlling late summer flows. Additionally, the Deep Creek Ditch, an interbasin diversion, supplies water to Minnesota Reservoir to satisfy the Reservoir Company's refill right. According to the officers of the various ditch and reservoir companies, the southern tributaries to Minnesota Creek (South Fork, Lake Fork, and Sam's Creek) are all subjected to diversion and contribute very little water during spring runoff and no water in the irrigation season. All water available at the Beaver Reservoir will not be diminished as a result of mining. Map 27 shows that the F Seam outcrops at the point where East Fork crosses the permit area. No mining will take place under the East Fork. As a result, the West Elk Mine will not affect the East Fork drainage. Because most or all of the water from the southern tributaries to Minnesota Creek is diverted by the various ditches, Minnesota and Beaver Reservoirs regulate a majority of the spring runoff in Minnesota Creek. During periods of low flow the reservoir releases into East Fork and Dry Fork comprise the total flow of Minnesota Creek. By not affecting the integrity of the reservoirs and their water supplies, Mountain Coal Company will be insuring that mining activities associated with the West Elk Mine will have no impact on the alluvial valley floor azeas along the main stem and East Fork of Minnesota Creek. During the site visit on September 9, 1980, the valley azeas of Dry Fork above Minnesota Reservoir and East fork above the South ForkBast Fork confluence and below Beaver Reservoir were visually inspected. It was agreed by all parties present that Mountain Coal Company's contentions • in the alluvial valley assessment aze valid. Isolated alluvial deposits aze also found within the nazrow valley of the North Fork of the Gunnison River upstream from its confluence with Gribble Gulch. These deposits consist of a few isolated high terraces that aze lazgely above the 100-yeaz flood plain and small discontinuous islands and terraces that aze within the confines of the 100-yeaz flood plan (Map 39). Unlike the East Fork of Minnesota Creek, evidence of agricultural developments were only found at several isolated locations, within the narrow valley of the North Fork (Map 66). The small discontinuous islands and terraces aze usually too small and too irregulaz in shape to support agricultural development. Also, the river poses numerous difficulties for fazming these locations, including access, flooding and changes in channel location. Soils Mapping Unit No. 27 is found on the terraces associated with the North Fork of the Gunnison River. Soils of this unit aze immature and exhibit no genetic soil horizontation. Mapping Unit No. 400 delineates the alluvial fan deposits developed at the confluences of the various side drainages, such as Sylvester Gulch, with the North Fork of the Gunnison River. The only location within the study azea where true alluvial soils were identified (Mapping Unit No. 300) is along the North Fork of the Gunnison River, off the azea to be mined. This mapping unit extends downstream along the south bank of the North Fork from the mouth of Lone Pine Gulch. A fairly lazge alluvial fan extends from the mouth of Sylvester Gulch into the SE '/< of Section 9, T13S, R90W. The lower portions of the fan were used by the Beaz family for storage of mine equipment and as their residence. Cross sections of the alluvial fan can be found in (Map 39). As can be seen, there is no evidence of terrace development. No further evaluation of this area was 2.066 Revised June 1005 PRIG; Rev. March 2006