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bounded by Larimide structural and physiographic features on the following sides: West Elk and Elk <br />Mountains on the east; the Gunnison Uplift on the south; the Uncompahgre Uplift on the west-southwest; <br />and the Grand Mesa-Piceance Basin on the north. <br />The geologic structure of the permit area exhibits an attitude of N66'W, with a 3 to 5-degree dip to the <br />northeast. There is one identified fault located in the southwest corner of the permit area. The fault trends <br />approximately N55'W and it dips 70 to 80 degrees to the northeast. The throw of the fault ranges from 7 <br />to 30 feet, with the downside located on the south side of the fault. <br />The coal in the area is situated within Mesaverde formation which contains interbedded sandstones, <br />mudstones, shales, siltstones and coal beds. The Mesaverde formation lies upon the Rollins Sandstone <br />Member of the Iles formation and below the Wasatch formation. The coal bearing member of the <br />Mesaverde formation locally contains up to nine (9) coal seams. These seams are located within a <br />stratigraphic interval of approximately 500 to 600 feet above the Rollins Sandstone. These coal seams are, <br />in ascending order, the A-Seam, the B- I Seam, the B-2 Seam, the C-Seam, the D-1 Seam, the D-2 Seam, <br />the E- I Seam, the E-2 Seam and the F-Seam. <br />The B-2 and D-2 Seams are mineable within the permit area. The D-2 Seam overlies the Rollins <br />Sandstone by 350 to 450 feet, and it ranges in thickness from about 8 to 16 feet. The B-2 coal seam lies <br />between the Rollins Sandstone and the D-2 coal seam and varies in thickness from 9 to 22 feet. Once <br />longwall mining in the D-2 coal seam was finished, and with the approval of Permit Revision No. 8, <br />longwall mining began in the B-2 coal seam. <br />Hydrology - <br />Detailed information regarding the surface and groundwater hydrology in and adjacent to the Bowie No. 2 <br />Mine permit area is provided within Sections 2.04.5 and 2.04.7 of the permit application document. A <br />brief summary is provided below, and the summary is derived from the information presented in permit <br />application Sections 2.04.5 and 2.04.7. <br />The permit and adjacent areas are generally bounded by three (3) perennial streams. These streams are <br />Terror Creek, Hubbard Creek and the North Fork of the Gunnison River, and the streams are located west, <br />east and south of the permit area, respectively. Tributary to the perennial streams are the following <br />intermittent and ephemeral streams: Freeman Gulch, Stephan Draw, A-Gulch, B-Gulch, C-Gulch, <br />D-Gulch, Dove Gulch and Sheep Corral Gulch. The specific locations of these streams are depicted on <br />permit application Map No. 9. <br />The North Fork of the Gunnison River drains an area of approximately 526 square miles. The average <br />annual yield of the North Fork of the Gunnison River from October 1993 to September 1994 was <br />approximately 330,500 acre-feet. The quantity and quality of this river is influenced significantly by <br />agricultural and municipal uses. Near Somerset, Colorado, the water in the North Fork of the Gunnison <br />River is a calcium-bicarbonate type, and total dissolved solids concentrations range from approximately <br />100 milligrams per liter (mg/ 1) to approximately 400 mg/l. <br />Terror Creek is a perennial stream which drains approximately 29 square miles, and Hubbard Creek is a <br />perennial stream which drains approximately 35 square miles. Freeman Gulch is a significant drainage <br />which is tributary to Hubbard Creek. Freeman Gulch exhibited flow during the snowmelt period of Spring <br />1995, and may be considered an intermittent stream. Stephan Draw is also an intermittent stream, and <br />Stockpond P-1 is located along Stephan Draw. <br />14