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-9- Three coal horizons exist in the Lower Coal-Bearing member, the "A" (Old King) horizon, the "B" (Somerset) Horizon, and the "C" (Bear) horizon. The "A" horizon is immediately above the Rollins sandstone and is not currently mined. The "B" horizon contains two coal seams and occurs about 20 to 120 feet above the Rollins sandstone. This horizon is presently mined by U.S. Steel at the Somerset Mine. The "C" horizon contains one coal seam that occurs 50 to 100 feet above the "B" horizon. This horizon has been mined at U.S. Steel's Elk Creek Mine and the Bear No. 1 and 2 Mines, and is currently mined at the Bear No. 3 Mine. The Upper Coal-Bearing (Paonia) member consists of 200 to 500 feet of gray shales, interbedded, buff-colored, lenticular sandstones, and coals. The top of this member is generally considered to be capped by a massive, cliff-forming sandstone. However, like the similar sandstone at the top of the Lower Coal member, this sandstone is not a single persistent bed. Drill hole data for both the Mr. Gunnison and the Somerset life-of-mine areas show different stratigraphic horizons. Three coal horizons have been identified in the Upper Coal member, the "D" (Oliver) horizon, the "E" (Hawk's Nest) horizon, and the "F" horizon.. The "D" horizon occurs directly above the massive sandstone of the Lower Coal-Bearing member and contains three seams. This horizon is currently being mined in the Orchard Valley Mine, and is planned to be mined at the Hawk's Nest Mine. The "E" horizon occurs about 130 feet above the "D" horizon and contains two coal seams. This horizon is currently being mined at the Hawk's Nest Mine and at the Blue Ribbon Mine. It may be mined at the Mt. Gunnison Mine and at the Bear No. 3 Mine in the future. The "F" horizon contains two coal seams and presently is only mined at the Mt. Gunnison Mine. Coal seams of the "F" horizon do not exist to the north of the North Fork in thicknesses sufficient for mining. The Barren (Undifferentiated) member of the Mesa Verde Formation consists of up to 1,600 feet of terrestrial sedimentary rocks. This unit consists of fine-grained, buff-colored, lenticular sandstones, gray shales and thin lenticular coal beds. The sandstones predominate and are highly lenticular, discontinuous and of limited lateral extent in outcrop (Johnson, 1948). A 2,500 foot thick sequence of sedimentary strata overlain by the Ohio Creek Conglomerate and underlain by the Mancos Shale. Beds exposed in the mine area dip 3-5 degrees north-northeast. The Bear Mine will extract coal from the "C" Seam, of the lower Coal Member of the Mesa Verde Formation. The Lower Coal Member averages 210 feet thick in the permit area and Bear's three minable coal seams. The member consists of interbedded sandstones, siltstones and coals, and is underlain by the Rollins Sandstone. A massive sandstone 25 to 225 feet thick overlies the "C" Seam and marks the top of the Lower Coal Member. The "C" Seam overburden ranges from less than 100 feet near the north edge of the permit area to over 1,400 feet in central and southern portions of the permit area.