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West Elk Mine <br />• mining area where only the E Seam coal is to be mined. These data have been used to calibrate <br />the subsidence prediction models described above. <br />In addition to relying on actual subsidence data, WWE has concluded that many of the fmdings <br />pertaining to subsidence and probable hydrologic consequences from previous pemut revisions <br />apply to the South of Divide pemut revision and mining azea. The basis for this conclusion is as <br />follows: <br />• Comparison of lithologic data from boreholes in the Jumbo Mountain, Apache Rocks and Box <br />Canyon mining azeas show consistency in the B Seam overburden materials, including those <br />units immediately above and below the E Seam coal. While direct correlation of lithologic <br />units, excluding coal beds, is generally difficult, comparison of lithologic logs shows very <br />similaz alternating sequences of shales, claystones, and sandstones. Based on the stratigraphic <br />and lithologic information obtained from drill holes in the South of Divide mining area, <br />the rocks consist of a greater proportion of shales, siltstones, and claystones than are <br />present in the Apache Rocks and Box Canyon mining areas. <br />• The South of Divide permit revision area is topographically similar to the Apache Rocks <br />and Box Canyon mining azeas although with a less extreme range of topographic relief. The <br />elevation range across the South of Divide permit revision area is from about 7,000 feet to <br />approximately 8,400 feet with fewer abrupt elevation changes than those seen in,the <br />Apache Rocks and Box Canyon permit areas, such as between the Sylvester Gulch <br />drainages and West Flatiroa Like these two previously permitted areas, the South of <br />• Divide permit revision area contains gentle as well as steep slopes making it susceptible to <br />rockfalls and landslides. <br />• Expected subsidence characteristics of the South of Divide permit revision area, based on <br />lithology and topogaphy, do not vary significantly from previous evaluations for B Seam <br />mining according to Mr. Dunrud, with the obvious exception of the reduced overburden <br />thicknesses associated with mining of the E Seam. Overburden thickness impacts will be <br />discussed later in this section. <br />Based upon these similarities, much of the information contained within the documents <br />pertaining to the Apache Rocks and Box Canyon permit revision area is applicable to the South <br />of Divide permit revision azea. Where differences occur, discussions of the resulting effects <br />have been provided. <br />Inventory of Structures and Renewable Resource Lands - 2.05.6 (6)(a)(i & ii) <br />In order to ascertain the impacts that subsidence will cause on structures and renewable resource <br />lands, an inventory of these features was conducted. Projected impacts to surface and ground <br />water resources aze presented later in Section 2.05.6(3). These water resources are shown on <br />Map 37. MCC's hydrologic monitoring stations and the many trails and unimproved U.S. Forest <br />Service roads utilized to access these sites aze shown on Map 34. <br />Man-made surface structures exist on the coal lease area and within the South of Divide permit <br />revision area (Exhibit 32B and Map 67). The only known structures which are currently used <br />• (intermittent seasonal use) are a cattle camp on the Dry Fork of Minnesota Creek with a <br />1.05-96 Revised June 2005 PRIO <br />