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by surface methods on the dip slopes, where overburden thickness allows for economic extraction within Twentymile Park around its margins, and where folding has elevated a major coal seam within the basin. Foidel Creek Mine is currently the only active underground operation within Twentymile Park. The mine is a longwall operation, using continuous miners for entry and development work only. The permit area encompasses approximately 22,694 acres. This permit renewal (RN-04) does not propose to enlarge the permit boundary or disturb new areas on the land surface. USGS Quadrangle maps of Milner and Rattlesnake Butte cover the majority of the permit area. Disturbed areas of the mine include the main surface facilities area along Foidel Creek and numerous smaller outlying facilities. These mine-related facilities result in 460 total disturbed acres. The main mine facilities lie in Sections 29, 31, 32, TSN, R86W of the 6th Principle Meridian and are located in, and adjacent to, a strip pit excavated originally by Colorado Yampa Coal Company's (CYCC) surface mining operation (No. C-81-071). Other facilities currently within the permit area, but sepazate from the main portal facility azea, include: the Fish Creek Borehole (FCB) facility, the Southwest ventilation facility (SW vent), the Eastem Mining District ventilation facility (EMD vent), the Eastern Mining District dewatering facility (EMD borehole), the Sandstones substation and North Escape Shaft, the Fish Creek Tipple (FCT) facility, the Eastern Mining District grout hole pad, and the Northern Mining District (NMD) vent shaft. The Fish Creek Borehole (FCB) is located on Fish Creek approximately 2 miles northwest of the main facility area in Section 25, TSN R87W. It consists oft dewatering boreholes, an inactive ventilation shaft, 3 treatment ponds, associated roads, a substation, a utility building, and water treatment equipment. The SW vent was reclaimed in 1996 and is located in Section 36, TSN R87W. The EMD vent facility is located in Section 14, TSN R86W and consists of two ventilation shafts (intake air and return air), intake air heating unit, associated buildings, powerlines, and fuel tank. The EMD borehole disturbed area is located in Section 21, TSN R86W and consists of a small pump building, a buried water return Tine and topsoil stockpiles. The Sandstones substation in Section 20, TSN R86W no longer serves as a power drop to the mine. The nearby North Escape Shaft has no facilities but exists as a completed 3 foot diameter shaft to be used only as an underground emergency extraction point for miners. The NMD vent shaft consists of associated buildings and a powerline. The Fish Creek Tipple (FCT) facility is located approximately 5 miles northeast of the main portal area in Section 2, TSN R86W, about 7 miles downstream on Fish Creek from the FCB facility. It was originally permitted separately under permit No. C-81-036 but since has been incorporated into the Foidel Creek permit No. C-82-056. It consists of a rail loadout, crushing and screening equipment, conveyors, stockpile areas, and a sediment control system of ditches and one pond. The FCT facility has been idle since Energy Mine No. 3 (No. C-84-062) completed mining in 1986, and is currently inactive. Locally significant are the rock units of Twentymile Park Basin which dip SN - 30N toward the central portion of the basin. Normal faulting has been identified throughout the permit area, striking generally northwest to southeast, with displacement of zero to 85 feet. A reverse fault running in an arcuate line northward through the west central part of the basin shows displacement of 0-80 feet. Smaller lateral faults were encountered in the 9R and l OR gateroads while driving development out into the Eastern Mining District. The near-surface bedrock units are composed of sedimentary rocks of marine and non-mazine origin. These sedimentary rocks were formed through the transgression and regression of an epicontinental sea and are comprised of sequences of sandstones, siltstones, shales and coal. Four geologic formations exist in the vicinity of the Eastern Mining District. They are, in ascending order, the Mancos Shale, the Iles and Williams Fork Formation of the Mesaverde Group, and the Lewis Shale. These strata were all deposited during the late Cretaceous Period. Generally, the strata dip to the center of the basin.