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The Rollins Sandstone is a white to buff-colored, well sorted, medium- to fine-grained <br /> sandstone, ranging from 150 feet to 300 feet thick. This sandstone is regionally extensive and <br /> resistant in outcrop and forms prominent cliffs. <br /> The Lower Coal Bearing (Bowie) Member consists of 260 to 350 feet of interbedded gray <br /> shales, thin to thick lenticular beds of buff-colored, fine- to medium-grained sandstones, and <br /> coals. Three coal horizons exist in this member, the A (Old King) horizon, the B (Somerset) <br /> horizon, and the C (Bear) horizon. The A horizon is immediately above the Rollins Sandstone <br /> and is not currently mined at any operation in the vicinity. The B horizon contains two coal <br /> seams and occurs about 20 to 120 feet above the Rollins Sandstone and will be mined by MCC <br /> during this permit term. This horizon has been mined and is currently being mined at the <br /> Somerset Mine. The C horizon contains one coal seam that occurs 50 to 100 feet above the B <br /> horizon. This horizon has been mined at U.S. Steel's Elk Creek Mine (now within the <br /> Sanborn Creek Mine permit area) and the Bear No. 1 and 2 Mines, and is currently mined at <br /> the Bear No. 3 Mine. The top of the member is usually capped by a massive buff-colored <br /> sandstone up to 90 feet in thickness. This sandstone, however, appears not to be a single <br /> persistent bed, but is actually several thick lenticular sandstones occurring at progressively <br /> lower stratigraphic horizons from east to west. <br /> The Upper Coal Bearing (Paonia) Member consists of 200 to 500 feet of gray shales, <br /> interbedded, buff-colored, lenticular sandstones, and coals. The top of this member is <br /> generally considered to be capped by a massive, cliff-forming sandstone. Three coal horizons <br /> have been identified in the Upper Coal Member, the D (Oliver) horizon, the E (Hawk's Nest) <br /> horizon, and the F horizon, The D horizon occurs directly above the massive sandstone of the <br /> Lower Coal Bearing Member and contains three seams. This horizon is currently mined in the <br /> Orchard Valley Mine. The E horizon occurs about 130 feet above the D horizon and contains <br /> two coal seams. This horizon has been mined at the Hawk's Nest Mine and was mined at the <br /> Blue Ribbon Mine. The West Elk Mine plans to mine the E Seam in the future. It will not be <br /> mined on Jumbo Mountain because the E Seam is split and comprised of several thin (< 5 ft.) <br /> coal benches which are separated by rock partings. The F horizon contains two coal seams <br /> and has been mined at the West Elk Mine. At the mine site, the coal is immediately overlain <br /> and underlain by shale. Coal seams of the F horizon do not exist to the north of the North <br /> Fork of the Gunnison River in thicknesses sufficient for mining. In the Jumbo Mountain area, <br /> the F Seam thins to less than five feet in thickness and is of limited aerial extent. Therefore, <br /> MCC does not plan to mine this seam in Jumbo Mountain. <br /> Overlying the Upper Coal Member is the Barren Member of the Mesaverde Formation. This <br /> unit consists of interbedded sandstones, siltstones, shales, and coals. The unit is not thought to <br /> be of marine origin and, as a result, the sandstones and the coals are highly lenticular, <br /> discontinuous, and of limited lateral extent in outcrop. This unit ranges up to 1,500 feet thick <br /> and outcrops throughout most of the five-year permit area. <br /> The Ohio Creek Member is the uppermost member of the Mesaverde Group. This unit is <br /> approximately 700 feet thick and consists primarily of interbedded sandstone, mudstone, and <br /> shale. The sandstones range from a few feet to more than 100 feet in thickness and are <br /> 11 <br />