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Fall 2009 Subsidence and Geologic Field Observations <br />Box Canyon, Apache Rocks, and South of Divide Mining Areas <br />• A photographic comparison between the July 2005 and October 2009 photographs show there to <br />be significant filling of the crack by weathering of the overlying colluvium and sandstone <br />outcrop. <br />5.4.2 Location 3 <br />Figure 14 is a photograph of a rockfall located above the drill road to West Flatiron as described <br />in previous annual and semi-annual reports. The fall, which occurred on June 30, 2004, is <br />located above the north edge of the central part of mined Longwall Panel 14. A photograph of <br />the same rockfall area taken during the summer of 2006 is provided in Figure 15 for comparison. <br />The overburden depth to the B-seam at this location is about 1,950 feet. Photographic <br />comparisons of this area since 2004 suggest that no additional subsidence related effects have <br />occurred. However, additional rockfalls due to natural processes may still occur in these rugged <br />cliff areas. As noted in Figure 14, there is evidence that portions of the rock pile located at the <br />base of the cliff face has moved and weathered to some degree and supports additional <br />• vegetation. <br />831-032.791 Wright Water Engineers, Inc. Page 26 <br />April 2010