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SPRING 2007 Subsidence and Geologic Field Observations <br />Box Canyon, and South of Divide Mining Areas <br />appraisal was completed of the Deer Creek Ventilation Shaft and Escapeway area as well as the <br />rockfall area near the Bear Mine portal in the C-Seam. These areas were again visited in April <br />2007 as a means to assess any potential changes to the area, make additional observations, and to <br />reconsider conclusions reached from the earlier evaluation. <br />Two new photographic observation locations (Photo Points) were established this year. The first <br />overlooks the Minnesota Creek Reservoir, Deer Creek Ventilation Shaft and Escapeway, and the <br />lower reaches of the Deer Creek drainage. This location will be used regularly to assess changes <br />that may occur as mining of the E-Seam progresses through the area. The second location is on <br />the west side of Sylvester Gulch and provides a good vantage point to view the headscarp of Box <br />Canyon. This location is approximately 3,000 feet north of the previous location established for <br />this purpose. <br />The previously established photographic observation location used to assess changes in the <br />Highway 133 landslides was not visited this spring. Vegetative changes associated with the <br />early spring (as opposed to midsummer) caused the authors to consider a reasonable <br />photographic comparison to be difficult. As a result, comparative photographs will be taken <br />during the fall Feld observations before leaves are off the deciduous vegetation. <br />Lastly, this report describes the newly installed E-Seam subsidence monitoring grid. This 119 <br />point subsidence grid is located over the E-Seam longwall panel 1 (El). Specific details <br />regarding the location of each point, the planned monitoring schedule, and data analysis ate <br />provided in this report. <br />5.0 TRAVERSES AND OBSERVATIONS IN THE BOX CANYON, APACHE <br />ROCKS AND SOUTH OF DIVIDE MINING AREAS <br />Detailed discussion of observations associated with Traverses A-A' through J-J' is provided <br />~' below (see Map I and 2). In many circumstances, photographs of locations observed during the <br />April 2007 field survey are compared to photographs taken in previous years. The photographs <br />taken during the most recent field observations are included as figures in the text of this report <br />'~ 831-032.780 Wright Water Engineers, Inc. Page 10 <br />July 2007 <br />