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I I <br />li <br />I i 4.3 <br />Subsidence Field Observations <br />West Elk Mine <br />July 22-24, 2003 <br />Subsidence Observations and Evaluations for July 24, 2003 <br />Location 9: <br />This point was located to evaluate and photograph the condition of the northwest part of <br />Minnesota Reservoir. <br />• The reservoir is located primarily in su~cial material (colluvium, alluvium, and soil) that has <br />moved down the Dry Fork of Minnesota Creek, down Horse Gulch, and down the side slopes <br />of the valley as slope wash and landslides (see video for more details). <br />• The reservoir level is very low. The flow of Minnesota Creek is allowed to pass through the <br />dam without restraint. <br />• The landslides west of the mouth of Horse Gulch and near the northern abutment of the <br />reservoir appear to be stable and unchanged compared with observations of the last two years <br />(Figure 13). <br />4.3.1 Traverse N-N' <br />Traverse N-N' is a foot traverse beginning at the main mad near Apache Rocks and ends at Drill <br />Hole SO.W-3. <br />• Walked above the approximate mid points of mined-out longwall Panels 13 and 13A. <br />• Sandstone, siltstone, and claystone of the Barren Member were observed along this old drill <br />road as well as areas of colluvium and soil. <br />• Overburden depth to the B-Seam ranges from 1,150 to 1,350 feet. <br />• The crack, as much as 6 inches wide-which was observed at Location 9 on this same <br />traverse in 2001-is no longer visible. This crack is also the crack displayed in Figure 16 of <br />the 2002 report. <br />831-032.610 Wright Water Engineers, Inc. Page 26 <br />i September 2003 <br />