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Subsidence Field Observations <br />West EIk Mine <br />August27-29,2002 <br />4.2 Subsidence observations and evaluations on August 28, 2002 <br />Traverses G-G' through J-J' were made along drill roads and trails in the West Flatiron-Deep <br />Creek areas (Map 1, also see video for further details). <br />4.2.1 Traverse G-G' <br />This traverse begins at point F (also at E') thence northwazd on top of West Flatiron and ends at <br />Drill Site I2AV-5. Observation locations 4 through 7 were established in order to record baseline <br />conditions in this rugged cliff-canyon terrain. <br />• Traverse is made above the un-mined projections of longwall Panels 24 through 19. <br />• Overburden depth to the B-Seam ranges from 2,100 to 2,200 ft. <br />• Soil, colluvium and sandstones and siltstones-shales of the Ohio Creek Member of the <br />Mesaverde Formation and clays of the Wasatch Formation were observed on this pre-mining <br />traverse. <br />Location 4: <br />This point is located at the old drill road to Drill Site 12AV-5, and also neaz a cliff outcrop of <br />sandstone on West Flatiron facing eastwazd towazds anortheast-trending tributary of Deep <br />Creek. <br />• Tension cracks as much as 3.5 inches wide and approximately 150 ft long are located in clays <br />of the Wasatch Formation along the old drill road to Drill Site RAV-5 (Figure 3, also see <br />video for more detail on cracks). <br />• The cracks look very much like subsidence cracks, but must be extension cracks caused by <br />lateral movement of bedrock towazds east-and west-facing cliffs (lateral spreading due to <br />gravitational forces). <br />831-032.570 Wright Water Engineers, Inc. Page 11 <br />December 2002 <br />