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the fall 2010 field visit (Map 2). <br />• Traverse K -K' above the eastern end of E -seam Longwall Panels E4 and E5 as established during <br />• <br />• <br />Spring 2011 Subsidence and Geologic Field Observations <br />Box Canyon, Apache Rocks, and South of Divide Mining Areas <br />5.4.1 Photographic Observation Point 12 <br />This photographic observation point was established along Dry Fork Road just below the culvert <br />crossing of Dry Fork and downstream of its intersection with the Horse Gulch road (see Maps 1 <br />and 2). This location provides a good view northeastward over the west end of E -seam Longwall <br />Panel El where sandstone outcrops and several vertical sandstone columns stand above the <br />surrounding vegetation. These structures represent features that can be periodically observed <br />while longwall mining occurs beneath this area. Overburden depth to the E -seam in the area of <br />the prominent rock outcrops is approximately 1,000 feet. <br />Figure 9 shows the overall view from this location during the fall 2009 field visit with an arrow <br />pointing to the area of prominent rock outcrops more fully displayed in subsequent telephoto <br />images from this same location during the fall 2009, spring 2010 and spring 2011 (Figures 10, 11 <br />and 12, respectively). These images show that one of the sandstone columns toppled between <br />fall 2009 and spring 2010 as E -seam Longwall panel El progressed westward under the area. A <br />comparison between images from spring 2010 and 2011 finds that there has been no change in <br />the area. <br />831 - 032.793 <br />September 2011 <br />Wright Water Engineers, Inc. Page 21 <br />