2010-05-03_REPORT - C1980007 (9)

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Fall 2009 Subsidence and Geologic Field Observations Box Canyon, Apache Rocks, and South of Divide Mining Areas 5.15 Traverse K2-K2' This traverse originates along the Dry Fork road and travels northward to drill pads for MDW E2-34 and E2-30.5. This traverse is over mined Longwall Panel E1 and unmined Longwall Panel E2 (Map 2). Overburden depth to the E-seam in this area ranges from 700 to 1,000 feet. Observation made during the fall 2009 trip represent baseline conditions with no evidence of slumping or cracking along the roadway or on the drill pads. Thick soil and colluvium derived primarily from the Wasatch Formation were observed along this traverse. 5.16 Traverse K3-K3' This traverse originates along the Dry Fork road near the lower Dry Fork flume and travels southeastward, on the north side (and parallel) of that road to three separate MDW drill pads (E2- 19, E2-23, and E2-26.5). This traverse is over planned Longwall Panel E2 where the overburden depth to the E-seam ranges from 600 to 800 feet. Observations made during the fall 2009 trip represent baseline conditions with no evidence of slumping or cracking along the roadway or on the drill pads. Thick soil and colluvium derived primarily from the Wasatch Formation were observed along this traverse. 5.17 Traverse L-L' Traverse L-L' is located along the Horse Gulch road from the fork in the Dry Fork road (east of Minnesota Reservoir) northward to the fork that leads to Apache Rocks (westward) and Sylvester Gulch (eastward). Two small slumps have historically been observed along the east (cutbank) side of the road along the northern end of this traverse. Regrading of these areas was observed to have occurred between our spring and fall 2009 visits. No subsidence related effects were observed along this traverse. • 831-032.791 April 2010 Wright Water Engineers, Inc. Page 62