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• Flintlock Pit Mining Area <br />The Baby Doe and Queen Anne draglines have been the primary stripping machines for this area. <br />Located in the East Pyeatt drainage, mining in these F-pit dip line cuts will advance to the east for the <br />2008-2012 permit term. Refer to the M10 series maps for a yearly detail of the mining and reclamation <br />sequences for the 2008-2012 permit term. <br />Kimber Pit Mining Area <br />The October 2006 landslide in the East Panel of Trapper Mine has resulted in a dramatic change in <br />planned mining methods at Trapper Mine. The K Pit and L Pit (f.k.a. G Pit) were originally planned as <br />dragline pits, consistent with Trapper's historic mining method. This pit layout is depicted on the M4 LOM <br />Map submitted and approved in PR-5. After extensive geotechnical study and mine planning efforts, it has <br />been determined that dragline mining is not a viable mining method for the K Pit due to the steeply dipping <br />structure. <br />After the East Panel landslide, Trapper retained Agapito Associates, Inc. (AAI) to perform geotechnical <br />investigation of the area to determine the causes and ramifications of the event. Numerous studies and <br />evaluations were performed by AAI personnel. A detailed analysis of AAI's findings is available in AAI's <br />January 2008 report, "Trapper G-Pit Landslide Mining Assessment° found in Appendix T. <br />The K Pit mining is now planned as a truck/loader operation. This method was selected as the safest <br />mining method and allows Trapper to recover coal resources in the affected area that would otherwise be <br />lost. Reserve estimates show approximately 8.6 million tons of recoverable coal in K Pit. Blocks B and C <br />of K Pit must be excavated to allow access to an additional 4.0 million tons in L Pit. Though this method is <br />a more expensive mining method, and requires a large capital purchase, it is the preferred mining method <br />for K Pit. This will result in a reclaimed landform that meets the requirements of Approximate Original <br />• Contours, and provides for long-term stability. <br />The general mine plan for the K Pit is to open the upper elevation of the mine area (designated as K Ridge <br />Pit) with a dragline. The slide plane has been determined to be a mudstone layer in the L seam roof. The <br />dragline bench for this pit will be below the subcrop of this seam, allowing the dragline to work from a <br />stable surface that is outside of the area affected by the slide. Dragline spoil will be cast into the area of <br />the Horse Gulch Fill. The truck/loader fleet will then open the B Blocks of the K Pit <br />Due to the steeply dipping pit floors, overburden removed by this fleet will be placed in permanent fills, <br />either the K Pit Buttress, or the Horse Gulch Fill. The B Block is, for all intents and purposes, a boxcut to <br />open the pit for mining. To minimize the chance of a spoil slide originating updip of the active mining <br />operation, a slide that could have the potential to endanger men and equipment, the K Pit Buttress and <br />Horse Gulch Fill are necessary. Upon completion of the B Block, the fleet will move to the C Block. Some <br />of this material will be placed in the Horse Gulch Fill; the majority will be used to backfll B Block. This <br />backfill will be placed to grade, as depicted on Sheet 3 of the M12 map. <br />L Pit (f.k.a. G Pit) Mining Area <br />L pit has been developed as a strikeline and dipline dragline pit over the years. L pit currently occupies <br />the eastern portion of the east panel landslide mass. Development of this pit will occur after the <br />completion of K pit stripping and will utilize a combination of truck and loader shipping and dragline <br />stripping. Development of L pit will occur early in the next permit term. It is necessary to develop blocks B <br />and C of K pit before reserves in L pit can be recovered. <br />Hawken Pit Mining Area <br />Mining in Hawken pit (H-pit) was completed in April 1997. After performing reclamation activities, the <br />• Queen Anne dragline walked to Ashmore pit in May 1997. <br />Revision: <br />q/Zfo? 3-15a <br />Approved: