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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 underground mains are primarily north-south and the longwall panels are oriented to be mined from west to east. Revision PR-02 increased the permit area to 14,812 acres and the affected area to 6,713 acres. The main surface facilities area along Foidel Creek, the Fieh Creek borehole, and the Fish Creek tipple occupy 338 disturbed acres. Hineral ownership ie 3973 federal acres, 4720 state acres, and 5118 private acres. Surface ownership ie 200 federal acres, 4000 state acres and 10612 private acres. The main mine facilities lie in Sections 29,31,32, TSN,R86W of the 6th Principle Meridian. USGS Quadrangle maps of Milner and Rattlesnake Butte cover the majority of the permit area. The proposed permit area lies on the south end of the regionally significant Sand Waeh structural basin. Locally significant are the rock unite of Twentymile Park Basin which dip 5° - 30° toward the central portion of the basin. Normal faulting has been identified throughout the permit area, trending 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. The near-surface bedrock unite are composed of sedimentary rocks of marine and non-marine 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 proposed Foidel Creek underground mine. They are, in ascending order, the Mancoe Shale, the Iles and Williams Fork of the Meeaverde Group, and the Lewis Shale (see Figures and 4 of this document). These strata were all deposited during the late Cretaceous Period. Generally, the strata dip to the center of the basin at about 7°. Three economically important coal seams, the Lennox, Wadge, and Wolf Creek coals, are located within the locally important, Middle Coal Group of the Williams Fork Formation. The Wadge coal seam will be mined in the Foidel Creek underground mine. The Wadge Coal seam was strip mined in CYCC's adjacent Energy No. 1 and Eckman Park Mines. The Wadge coal seam, in the area of the Foidel Creek Mine, is separated from the underlying Trout Creek sandstone by about 250 feet of interbedded eandetonee, eiltetones, shales and coals. The Wadge coal seam is separated from the overlying Twentymile sandstone by 700 feet of massive shale and interbedded eandetonee, siltetones, shales and coals. Overburden depths in the proposed permit area range from 0 to 1,700 feet (see Map 6 of the permit application). The etratigraphy and geologic structure within the Twentymile Park Synclinal Basin control the ground water flow within the permit and adjacent areas. There are three regional bedrock aquifers within the permit and adjacent areas of the Foidel Creek underground mine. These aquifers are the Trout Creek sandstone, the Twentymile sandstone, and the Wadge coal-overburden zone. All three aquifers exhibit artesian conditions in central portions of Twentymile Park Basin. The quality in all aquifers ie moderately poor and is tolerable for use as a drinking supply. The folding and faulting (geologic structure) within the Twentymile Park Synclinal Basin affects the direction of flow within the rock aquifers. In the permit and adjacent areas, the ground water flow in the bedrock aquifers is down the dip to the northeast into the Twentymile Park Basin. Faults in the area produce localized fracture zones within the rock strata. These zones of increased permeability, in turn, increase the potential for vertical and horizontal movement of ground water within the rock strata. However, to-date