2008-04-15_REVISION - M1980244 (309)

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• Using the NRCS data, eight soil types were identified within the MLE study area (Grenadier-like-Unnamed soils, Quander-Varden Complex, Rogert soils, Ess-Bushvalley, Ivywild-Catamount, and Seitz). The Rogert soil type was further divided into three sub- units. Most of the soil units mapped in previous soil surveys remain valid; however the NRCS has revised soil units and descriptions. The 1997 JBR survey identified and mapped hydric soils in the MLE study area. A review of the most current NRCS soil unit maps indicates that the hydric soils correspond closely to soil unit CQ (Adderton-Cryaquolls). Areas that were historically mined or otherwise altered by human activity were identified as disturbed soils. All of the mapped soil units are shown on Figure 2-1 of Appendix 3 in Volume III of this document. All soils in the area are characteristic of well drained mountain soil complexes found on steep slopes and exhibiting low water capacity, rapid surface water runoff, and a susceptibility to water erosion. The soils are differentiated based on slope and aspect and support different vegetation types. Each of these soils is described in detail, including the thickness of the soil horizon for each type and the suitability of each type for use in reclamation, in Appendix 3 in Volume III of this document. • Range carrying capacities have been determined to be an average value of 3.1 acres per Animal Unit Month ("AUM") for the Quander-Varden complex, 3.8 acres per AUM for the Rogert soil, and 1.3 acres per AUM for the hydric soils. Most of the soil groups presented above are suitable for use in reclamation. As part of the ongoing mining operations at the Cresson Project, CC&V salvages soil that is suitable for assisting with revegetation in accordance with its reclamation objectives of revegetation on suitable slopes (see Reclamation and Closure, Section 11.0 of this Project Description). Note that the soil depth information presented in Table 2-2 of Appendix 3 is not strictly indicative of soil depths that can be salvaged. The actual depths are functions of slope, surface rock, aerial extent, vegetative cover, and historical mining. Soil depths vary greatly depending upon their position on the terrain, with the shallowest soil on the upper slopes and deepest at the toe of the slope. The presence of rock outcrops in some areas renders salvage operations impossible. By removing large roots, stumps, and pushing slash, unavoidable mixing of the thin topsoil with the rocky subsoils occurs, producing a material potentially not well suited for salvage as soil. The depth that can be recovered also is a function of the nature of the soil and weathered bedrock, and the capabilities of the dozers and other mechanized salvage equipment. As discussed in • Cripple Creek & Victor Gold Mining Company Cresson Project Mine Life Extension 4-18