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Fall 2007 Subsidence and Geologic Field Observations <br />Box Canyon, Apache Rocks, and South of Divide Mining Areas <br />Nine photographic observation points were established in 2007. Two photographic observation <br />points were established during the spring fieldwork. Seven more were established during the fall <br />field visit. The spring photographic observation points include one that overlooks the Dry Fork <br />drainage, the Minnesota Creek Reservoir, the Deer Creek Ventilation Shaft and Escapeway, and <br />the lower reaches of the Deer Creek drainage. This location will be used regularly to assess <br />changes that may occur as mining of the E-seam progresses through the area. The other spring <br />photographic observation point is on the west side of Sylvester Gulch and provides a good <br />vantage point to view the rockfall and landslide area at the headscarp of Box Canyon. This <br />location is approximately 4,300 feet north of the previous location established for this purpose. <br />Seven additional photographic observation points were established in the fall to view rockfalls <br />and landslides in the Box Canyon mining area, the dam and landslide construction in the <br />Minnesota Reservoir area, and the Highway 133 landslides (see Map 1 for all these locations and <br />associated number designations). <br />The previously established photographic observation point used to assess changes in the <br />Highway 133 landslides was visited during the fall. Vegetative changes associated with the early <br />spring caused the authors to consider a reasonable photographic comparison to photographs <br />previously taken in midsummer to be difficult. Comparative photographs were taken during the <br />fall field observation (September 28, 2007) while the leaves were still on the deciduous <br />vegetation. <br />This report also describes the newly installed E-seam subsidence monitoring grid. This 119- <br />point subsidence grid is located over the E-seam longwall panel 1 (E1). Specific details <br />regarding the location of each point, the planned monitoring schedule, and data analysis are <br />provided in Appendix B of this report. The baseline survey measurements of the lowest points <br />of the Dry Fork stream bed (thalweg) is provided in Appendix C of this report. <br />831-032.780 <br />November 2007 <br />Wright Water Engineers, Inc. <br />Page 13 <br />