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West Elk Mine <br />and may provide recreational opportunities for semi-primitive non-motorized, semi-primitive <br />motorized and roaded natural settings. The Gunnison National Forest prohibits cross-country travel in <br />motorized vehicles. <br />It is anticipated that little or no impacts to wildlife and domestic livestock uses, and their respective <br />habitat will occur as a consequence of mining-induced subsidence on the permit area. In the <br />unlikely event that subsidence effects adversely impact wildlife or domestic livestock uses <br />associated mitigation measures will focus on returned disturbed areas to a capability and land use(s) <br />which existed prior to mining. These mitigation measures are discussed in detail in Section <br />2.05.6(6)(f)(iv)(A-D) - Detailed Description of Mitigating Measures. <br />Effects of Minim- on Surfcial Geologic Features <br />When evaluating the effects of mining in the permit revision area, the present land use, the post- <br />mining land use and the effects of previous mining in the area should be considered. Present land <br />uses primarily include wildlife habitat, recreational hunting, and livestock grazing. Post-mining <br />land uses will be essentially the same. <br />Evaluation of the effects of past and current longwall mining on surface features indicates that surface <br />cracks and visible surface effects are relatively rare (see Map 67) and have been documented as <br />follows: <br />1. Numerous cracks occurred in the meadow above and south of the West Elk Mine surface facilities. <br />Some question exists as to whether these represented subsidence cracks or resulted from slight <br />movement of the large landslide complex. Even if they were subsidence cracks, the cracks resulted <br />from room-and-pillar mining, not longwall nursing, as the cracks occurred above the F Seam room- <br />and-pillar areas shortly after they were reined, and north of the area of influence of longwall <br />reining. <br />2. Cracks occurred on the point of a high ridge immediately north of the forks of Lone Pine Gulch <br />near the center of the south line of Section 17. Cursory surface investigation found no evidence <br />that the cracks extended into the shales below a prominent sandstone ledge. Assessing the <br />subsidence cause and relationships of these unique cracks is difficult. These cracks occurred along <br />the south boundary of room-and-pillar B and C Seam mining by Bear Coal Company, along the <br />north boundary of MCC F Seam room-and-pillar mining and 700 feet north and east of the <br />boundaries of MCC's B Seam longwall panels. The cracks occur above the narrow, rigid boundary <br />pillar. The cracks may be the result of any or a combination of all of the above activities. <br />According to C. R. Dunrud. these cracks are larger than any he save in his previous extensive <br />subsidence research in the entire North Fork Valley. <br />3. In the fall of 1994, a series of cracks appeared along an unimproved road south of Lone Pine Gulch <br />near the center of the NA Y'1,''4 of Section 20_ The cracks occurred near the center of the north half <br />of the 5NW long-wall panel and above the N?,estern boundary of previous room-and-pillar mining of <br />the F Seam. Careful study by Mr. Dunud indicated that the most likely, but not conclusive, <br />explanation of the cracks Nvas that subsidence had reinitiated slight movement in old landslide <br />deposits. <br />2.05-110 RevisedJune2005 PRIG. Rev. Harch 2006: Rev. Apri12006PRJO:.n ay2006PR1O, Nov. 2006TR107, Sep. 2007PR-12;Feb.2008PR-12