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• Mountain Coal Company Exhibit 27 West Elk Mine Characteristics of West Elk Mine Soil Mapping Units These are the more moist counterparts of group ? or the dryer lower elevations. They occur at elevations of approximately 6.800 to 7,800 feet throughout the sur`ey area but occur in the most acreage in the central and northern parts of the mine area. They occur in the same landscapes and in association with the soils of group 3 but normally occupy the more stable upland ridge or hill crests and sides where soil development has been active long enoueh to develop mature soil horizonation. Normally, they have friable, granular, noncalcareous. neutral to mildly alkaline surface horizons (A horizons) eight to 36 inches thick that are grayish brown to dark grayish brown when dry and very dark grayish brown, very dark brown. or black when wet. Surface horizons grade to brighter colored, slightl}~ tiner textured, blocky subsurface horizons (B2t horizons) 15 to 30 inches thick that show evidence of silicate clay translocation and accumulation as coatings and flow surfaces on pad faces and as fillings in root channels and pores. Underlying C horizon material is generally noncalcareous and only slightly coarser textured than the subsurface horizons. Calcareous horizons below the 62t horizon and visible accumulations of calcium carbonate do occasionally occur and have not been excluded from the soils of this morphological group. • Morphological Group 6 Soils in morphological group 6 are weakly developed and cold, have dark surface horizons (A horizons), and occur at high elevations (above 7,800 feet). This group includes mapping units X6, X25, and X26. The soils of morphological group 6 are the cold counterparts of those of morphological group 3. They occur principally in the eastern, north central, and southern parts of the mine area at elevations in excess of 7,800 feet. They are cold soils having mean annual soil temperatures of less than 47 °F and mean summer soil temperatures of less than 59 °F. Annual precipitation is greater in these areas than in the areas of low or intermediate elevation. In addition, evapotranspiration rates are lower and demands for soil moisture are less extreme because of colder temperatures and shorter growing seasons. Morphological Group 7 Soils in morphological group 7 are maturely developed and cold, have dark surface horizons (Al horizons), and occur at high elevations (above 7,800 feet). This group includes mapping units X30, X31, and X32. With a few minor exceptions, the soils of morphologica] group 7 are the cold counterparts of the soils of morphological group 5. They occur principally in the north • central, eastern, and southern parts of the mine area at elevations in excess of 7,800 feet. They are cold soils having a mean annual soil temperature of less than 47 °F and a mean summer soil temperature of less than 59 °F. Annual precipitation is greater in these areas Exhibit 27-36