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Spring 2009 Subsidence and Geologic Field Observations <br />Box Canyon, Apache Rocks, and South of Divide Mining Areas <br />• Light gray to brown soil, alluvium, and colluvium of the Barren Member of the Mesaverde <br />Formation are exposed along this road traverse. The soil, alluvium and colluvium are generally <br />stable due to the relatively gentle grade of the Sylvester Gulch valley bottom. <br />No subsidence features were observed and no photographs were taken. <br />5.3 Traverse C -C' <br />Traverse C -C' begins at the well site for E -seam methane well no. 1 (ESM -1) over mined B -seam <br />Longwall Panel 13, travels along the main access road to the Box Canyon mining area and West <br />Flatiron, and ends at the fork in the drill roads (at D of Traverse D -D' and I of Traverse I -I') <br />above the southern edge of mined Longwall Panel 14 (Map 1). <br />This traverse winds its way above mined Longwall Panels 13, 13A, 17, 16, 15 and 14. Light gray <br />to brown soil, colluvium, and local outcrops of siltstone and sandstone of the Barren Member of <br />the Mesaverde Formation occur in the road cuts. Overburden depth to the B -seam varies from <br />• 1,000 to 1,650 feet. The colluvium and soil are locally unstable on the road cuts in the steeper <br />areas along the traverse, which causes landslide deposits, primarily on the commonly - occurring <br />steep slopes along the middle portion of the traverse. <br />No subsidence features were observed. <br />5.4 Traverse D -D' <br />Traverse D -D' begins at point C' of Traverse C -C' (and point I of Traverse I -I') above the southern <br />edge of mined Longwall Panel 14 and ends at the fork in the drill roads above the southern edge <br />of mined Longwall Panel 24. Soil, colluvium, and local bedrock of the Ohio Creek and Barren <br />Members of the Mesaverde Formation are exposed in the drill road. The soil and colluvium are <br />locally unstable or quasi - stable on the steepest slopes. <br />The overburden depth to the B -seam ranges between 1,625 and 2,175 feet. Observed subsidence <br />related features along this traverse included a crack at Location 2 (first observed in 2004) and a <br />• June 2004 rockfall at Location 3 (Map 1). <br />831 - 032.791 Wright Water Engineers, Inc. Page 23 <br />November 2009 <br />