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Fall 2008 Subsidence and Geologic Field Observations <br />Box Canyon, Apache Rocks, and South of Divide Mining Areas <br />4.0 OVERVIEW OF FALL 2008 FIELD STUDIES <br />This subsidence report is the second of two reports generated during the 2008 calendar year. <br />Biannual reports were initiated in spring 2007. According to the permit, such reporting is to be <br />submitted to Colorado Division of Reclamation, Mining and Safety (CDRMS) by April 30tn <br />(spring) and October 31St (fall). However, springtime observations are regularly hampered by <br />limited access due to snow or muddy conditions as occurred this year. For example, persistent <br />snowstorms and snowpack prevented field observations this April while prolonged cooler <br />weather caused additional snow and muddy conditions throughout much of May. As a result, the <br />spring 2008 field work was not conducted until early June. Given the lateness of the spring field <br />work, it was decided to conduct the fall field work in October. This fall report describes the field <br />observations made during the October 2 and 3, 2008 field visit (i.e., the second time that most of <br />the subsidence monitoring areas have been observed during the fall). <br />Subsidence observations were conducted in the Box Canyon, Apache Rocks, SOD, and Dry Fork <br />mining areas. Field observations were made from a 4-wheel drive vehicle and by foot travel to <br />efficiently complete the required work. <br />Prior field observations and experience in the West Elk Mine area during field studies over the <br />last thirteen years' (1996 to 2008 inclusive) indicate that subsidence features (cracks and bulges) <br />are most visible on roads and trails, where the ground is more compact and free of brush. These <br />areas were therefore selected, in addition to undermined areas free of brush, in order to most <br />efficiently obtain maximum subsidence information. <br />Annual subsidence and geologic hazard reports are kept at Mountain Coal Company, LLC and at the Colorado <br />Division of Reclamation, Mining, and Safety, as well as exhibits to the permit document (Exhibits 60, 60A, 60B, <br />60C, 60D, and 60E). <br />831-032.790 <br />December 2008 <br />Wright Water Engineers, Inc. <br />Page 14