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Descriation of the Environment <br />The CYCC operations currently permitted under permit # C-81-071 aze located 20 to 25 miles <br />southwest of Steamboat Springs in Routt County, Colorado. The proposed permit area varies <br />in elevation from 6,600 feet in the eastern portion of the azea along Foidel Creek to over <br />8,200' in the southwestern part of the proposed permit area. The topography is dominated by <br />long gentle slopes formed by uplifted strata of mainly Cretaceous age, with prominent cliffs <br />occurring where massive sandstone units outcrop. Flatter topography resulting from alluvial <br />deposition is evident in the valleys of Fish Creek, Foidel Creek and Middle Creek, which aze <br />the major drainages in the permit area. <br />The proposed permit area lies on the south end of the regionally significant Sand Wash <br />structural basin. Locally significant are the rock units of the Twentymile Park Basin, which <br />dip 5~-30~ toward the center of the basin. Normal faulting has been identified throughout the <br />permit area, trending northwest to southeast, with displacement of zero to 85 feet. A reverse <br />fault trending northwazd through the west central part of the basin displays displacement of <br />0-80 feet. <br />The geology of the area is composed of sedimentary rocks of mazine and non-marine origin. <br />These sedimentary rocks were formed through the transgression and regression of an <br />epicontinental sea during the Cretaceous Period and aze comprised of sequences of sandstones, <br />siltstones, shales and coal. <br />Four geologic formations exist in the vicinity of the proposed permit area. They aze, in <br />ascending order, the Mancos Shale, the Iles and Williams Fork Formations of the Mesaverde <br />Group, and the Lewis Shale (Permit Figures 1 and 2). These strata were all deposited during <br />the late Cretaceous Period. The strata dip to the center of the basin, at approximately 7 <br />degrees. <br />Rock units and thicknesses from oldest to youngest aze: <br />I. Trout Creek Sandstone (50-100') -fine grained, massive sandstone; <br />2. Wolf Creek Underburden (30') -predominately fine-grained sandstone and silts[one with <br />minor interbedded shales; <br />3. Wolf Creek Coal (11-21') - vaziable sulfur, sub-bituminous coal to be mined in the <br />eastern part of the proposed Little Middle Creek tract; <br />4. Wolf Creek Overburden (approximately 160') -predominantly sandstone and siltstone <br />with interbedded claystone and shales; <br />5. Wadge Coal (7-11.5') -low-sulfur, sub-bituminous coal to be mined in the western <br />portion of the permit area; <br />6. Wadge Overburden (60-90') -interbedded, sandstones, siltstones and shales; <br />7. Lennox Coal (0-2') -discontinuous coal seam; <br />8. Lennox Sandstone (0-10') -discontinuous, lenticulaz sandstone; <br />9. Lewis Shale (approximately 700') -massive, mazine shale; and, <br />10. Twentymile Sandstone (100-200') -massive, white sandstones. <br />6 <br />