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Fall 2008 Subsidence and Geologic Field Observations <br />Box Canyon, Apache Rocks, and South of Divide Mining Areas <br />• 5.6.2 Photographic Observation Point 2 <br />• <br />Location 8 is also the site of Photographic Observation Point 2. For the past several years this <br />photographic observation point has been used to observe a rock fall landslide area located 4.400 <br />feet south in the upper. massive sandstone cliff of the Ohio Creek Member of the N[esmerde <br />Formation (Location 10 on Flap I). Figure 19 shows this area as observed from this location. <br />Comparisons to previous photogaphs from this location show there to be little change (see <br />Figure 25 of the fa112008 and Figure I of the spring 2007 subsidence monitoring report). <br />Figure 19. Southward, fall 2008, view from Photographic Observation Point 2 of a rockfall/landslide <br />area in a massive sandstone cliff of the Ohio Creek Member of the Mesaverde Formation (i.e.. <br />Location 10). The area is located about 1,800 feet above the tailgate road pillars of mined <br />Longwall Panel 22. The excavated area above the rockfall/landslide area (upper right) is the drill <br />pad for MDWs 22-05 and 22-06 (i.e., the terminus of Traverse H-H'). <br />• <br />5.6.3 Location 9 <br />This is the rock fall landslide site above the mined Lon?o%yall Panel 19 headgatc/Panel 20 tailgate <br />as first observed in spring 2008. 13-seam overburden thickness at this location is about 2,200 <br />feet. The rockfall source is the upper sandstone of' the Ohio Creek Member of the ivlesa\erde <br />Formation. The relatively small rockfall/landslide is as shomi on Map 3. <br />831-032 790 Wright Water Engineers, Inc. <br />December 2008