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6.4.9 EXHIBIT I -Soils Information The affected area lies at an elevation of 8,300 feet and has slopes ranging from nearly level to over 40%. The area was mapped by the USDA Soil Conservation Service (SCS now NRCS). Descriptions given below are based on an adaptation of the available NRCS data. A soils map showing the general delineation of the soils present in the permit and surrounding area follows this section. Generally, the Soil Survey of Rifle Area, Colorado lists this area aParachute-Rhone- Irigul, deep to shallow, well drained, moderately sloping to steep soils on mountains and ridges. The proposed gravel pit is mainly located in the Irigul soils. Map Unit 36 Irigul channery loam, 9 to 50 percent slopes This shallow well drained rolling to steep, soil is on upland ridges and mountainsides. Elevation ranges from 7,800 to 8,700 feet. This soil formed in residuum from sandstone and marlstone. The average annual precipitation is 20 inches and comes mostly as snow. The average air temperature is 40 degrees F, and the average frost free period is less than 75 days. Typically, the surface layer is grayish brown channery loam about 6 inches thick. The underlying material is yellowish brown extremely channery sandy clay loam about 11 inches thick. Hard, fractured sandstone is at a depth of 17 inches. Included in this soil in mapping are small areas of soils that are more than 20 inches deep to bedrock, some small areas of soils that have a light colored surface layer, and some small areas of rock outcrop. Permeability is moderate, and available water capacity is very low. Effective rooting depth is 10 to 20 inches. Surface runoff is medium, and erosion hazard is slight. This soil is used for wildlife habitat and limited grazing. The native vegetation on this soil is mainly wheatgrass, bluegrass, mountainmahogany, and serviceberry. Map Unit 52 Parachute loam, 25 to 65 percent slopes This moderately deep, well drained, hilly to very steep soil is on north and east-facing mountainsides. Elevation ranges from 7,500 to 8,700 feet. This soil is formed in residuum from sandstone. The average annual precipitation is 20 inches, the average air temperature is 40 degrees F, and the average frost free period is less than 75 days. Typically, the surface layer is grayish brown loam about 5 inches thick. The upper part of the subsoil is very dark grayish brown and brown loam about 13 inches thick, and the lower part is light yellowish brown extremely channery loam about 11 inches thick. Hard fractured bedrock is at a depth of 29 inches. Included in this soil mapping unit are small areas of Rhone and Irigul soils. The Rhone soils are in concave positions. These areas make up 10 to 15 percent of the map unit. Irigul soils are on ridge crests.