2013-04-10_GENERAL DOCUMENTS - C1981019

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3.2.4 Topography The East Pit, West Pit and Section 16 Pit mining sites lie just west of the northward flowing Goodspring (also referred to as Good Spring) Creek, which is paralleled by Colorado Highway 13. The area is a gently sloping upland ranging from about 7,640 feet near the southwest corner to 6,560 feet near the northeast corner of the permit area. Valleys that cut into the upland surface are generally narrow, V- shaped, and about 250 to 500 feet deep. The topographic surface north of the proposed East Pit, West Pit and Section 16 Pit mining sites is dominated by two ridges about two miles long, trending north - northeast, bounded by Goodspring, Taylor and Wilson Creeks. The South Taylor Mining area lies north and west of the northward flowing Goodspring Creek, which is paralleled by Colorado Highway 13. The area is also just south of the northward flowing Taylor Creek, which runs adjacent to the current Section 16 and West Pits. Much of the area is gently sloping upland rangeland from approximately 8,400 feet to 7,900 feet. Much of the area on the perimeter of the South Taylor mining area is steeply sloping, with slopes in excess of 20 %. The Collom expansion area is located west of the West Pit, and expands the current western permit boundary to just west of Collom Gulch. It is bounded on the west by Morgan Creek, and includes Collom Gulch, Little Collom Gulch and Jubb Creek. Elevations in the Collom expansion area range from just below 6,400 feet +/- mean sea level (msl) to approximately 8,567 feet. Slopes in the Collom expansion area range from moderately steep to steep ( >35 %) drainages, and benches between the drainages, sloping northeasterly from 1% to 5 %. The predominant land use in the Collom expansion area is rangeland /fish and wildlife habitat, with smaller acreage characterized as pastureland. 3.2.5 Geology Geologic information is found in Sections 2.04.6, Maps 7 through 9A, and Exhibit 6 of the PAP. The permit area and Collom expansion area lies about south of the axis of the Axial Basin Anticline, a large northwest- trending fold found in the southern Uinta region of the Piceance Basin. The southern limb of the Axial Basin anticline is shared with the Collom syncline. The anticline structure and corresponding syncline (Collom Syncline) to the south consist of thousands of feet of marine deposited sediments of Cretaceous age. To the south of the anticline, the axis of the Collom Syncline, a downward fold, passes directly through the permit area, trending north 70 degrees west and plunging from 0 to 20 degrees to the North. In the northeastern corner of the permit area, near Streeter Fill, the Collom Syncline is influenced by the Elkhorn Syncline which results in strata having an eastward dip and north - south strike (see Map 7 and Figure 1 in the PAP). There appears to be no evidence of faulting in the permit area; however, linear features that may Colowyo Coal Mine C1981 -019 PR -03 22 April 10, 2013