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For adjacent undisturbed areas, slope angles were drawn from the area • immediately adjacent to the reclaimed or revegetated area. Slope lengths for undisturbed areas were selected from the same transect line as the undisturbed slope angle. Undisturbed slope measurements were selected to be close (in length) to those identified within the reclaimed or revegetated areas. The slope angles and lengths for the analysis are provided below. Location Slope Length Slope Angle Lone Pine UDWP 130' 21 ° Lone Pine Topsoil Pile 90' 26° Lone Pine Staging Area 70' 35° Lone Pine UDWP undisturbed area 100' 14° Lone Pine Topsoil Pile undisturbed area 100' 14° Lone Pine Staging Area undisturbed area 70' 35° Water Tank reclaimed area 75' 16° Water Tank undisturbed area 75' 16° COVER AND MANAGEMENT FACTOR (C) • Ir 1 LJ The cover and management factor in the USLE accounts for the effect of plant and litter cover on the ground surface in reducing erosion by intercepting raindrops and reducing direct contact with the soil. For the varying vegetation types such as that at the West Elk Mine, Table 1 was used in conjunction with the 1997 vegetation data to develop the appropriate factor values. The mean total vegetation cover of the Underground Development Waste Pile was 43.50 percent, comprised largely of sod-forming and bunch grasses with spreading bases. Additional significant cover is provided by the much branched and spreading forbs, Achillea lanu/osa (western yarrow) and Polygonum douglasii (knotweed) with a combined cover of 6.00 percent. These types of vegetation provide significant cover contacting the ground surface. Grasses provide 84 percent of the mean total vegetation cover, with the remaining 16 percent provided by forbs. Litter contributes 50.00 percent ground cover. The UDWP reclaimed area falls within the "no appreciable canopy" category of Table 1. Assuming 94 percent ground cover (43.50% vegetation cover, 50% litter, and 0.50% rock), the C factor for the UDWP reclaimed area is estimated at 0.0035. At the revegetated Topsoil Pile, vegetation cover was 60.67 percent. As with the UDWP azea, cover was predominant]y grasses (49.33%), and forbs (9.33%). Litter provided 33.33 percent ground cover. As with the UDWP area, the C factor was selected from the --"no appreciable canopy" category of Table I. Percent ground cover was 94 percent, composed of grasses and forbs, indicating a C factor value of 0.0035. The Staging Area at the Lone Pine Gulch Surface Facilities Area was situated on a steep north-facing slope. Vegetation cover was more sparse on the upper areas of the ~-