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Fall 2008 Subsidence and Geologic Field Observations <br />Box Canyon, Apache Rocks, and South of Divide Mining Areas <br />0 5.7 Traverse G-G' <br />Traverse G-G' is a new short traverse that begins along Traverse F-F' near the fork in the main <br />West Flatiron drill road and heads northwesterly to a drill pad containing MDW 18-34. This flat <br />traverse is above the eastern part and northern entries of mined Longwall Panel 19 and primarily <br />in clays and silts of the Wasatch Formation. Overburden depth to the B-seam is 2,200 to 2,250 <br />feet. <br />No subsidence related features were observed along this traverse and no photographs were taken. <br />5.8 Traverse H-H' <br />Traverse H-H' begins at a fork in the main West Flatiron drill road and ends at the drill pad for <br />MDWs 22-05 and 22-06, which is disassembled. This short traverse starts above the northern <br />edge of mined Longwall Panel 23 and ends above mined Longwall Panel 22. Soil, colluvium, <br />and silty claystone, derived primarily from the Wasatch Formation, were encountered. The <br />overburden depth to the B-seam ranges from 2,200 to 2,250 feet. No subsidence features were <br />observed along this route. <br />This traverse includes Location 10 (photographed from Photographic Observation Point 2) which <br />cannot be viewed along this route but is located topographically lower and northeast of the drill <br />pad for MDWs 22-05 and 22-06 (Map 1). <br />This traverse also includes two annual observation locations: 1) to view and document the upper <br />part of the rockfall/landslide areas on the east side of Box Canyon above Longwall Panels 19, 20 <br />and 21 (now established as Photographic Observation Point 3), and 2) to observe the headscarp <br />of an eastern side drainage in Sylvester Gulch (Location 11). <br />5.8.1 Location 10 <br />This is a rockfall/landslide area, which was observed from Photographic Observation Point 2 <br />(Section 5.6.2), is located above the rigid three-pillar entry system that separate Panels 18, 19, 20 <br />and 21 (to the north) from Panels 22, 23, and 24 (to the south). The rockfall/landslide is <br />831-032.790 Wright Water Engineers, Inc. Page 37 <br />December 2008