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-7- Description of the Environment The 1,360 acre Bear No. 1 and Bear No. 2 permit area and the 287 acre Bear No. 3 revision area (which will be mined during the permit term) lie within the drainage of the North Fork of the Gunnison River which is tributary to the Colorado River System. The area is mountainous, with elevations ranging from 6,000 feet at Somerset to 12, 719 feet at the summit of Mt. Gunnison, to the south of the permit area. The North Fork has cut a deep canyon through the area which separates high tablelands south of the river from the slopes of the Grand Mesa to the north. The canyon is narrow and steep-sided in the vicinity of the Bear mine, widening out into a broad alluvial valley in the vicinity of Paonia. The tableland to the south of the North Fork is deeply dissected by tributary streams, and is bounded on the south and east by the West Elk Mountain Range. The climate of the region is typical of the Rocky Mountain area. The valley in which Paonia and Somerset are situated is semi-arid with annual precipitation averaging about 15 inches per year. Mean annual precipitation increases with elevation, reaching approximately 40 inches per year on the summit of Mt. Gunnison. The May-September precipitation is 5 inches for the lowlands and 13 inches for the mountain peaks. This indicates that snowfall patterns play an important part in determining the hydrology of the area. Temperature extremes at Paonia have ranged from -28o F in January to IOOo F during July and August. The average annual temperature is approximately 49o F. Snowfall averages 58 inches per year. The North Fork of the Gunnison is the major drainage for the mine site. Four ephemeral streams drain the permit area, and join the North Fork in the vicinity of Somerset. The water in the North Fork is characterized as a calcium bicarbonate type with moderate levels of sulfate. No alluvial valley floors (AVF's) exist within the permit area. Alluvial deposits along the North Fork below the town of Somerset have been found to meet the geomorphic criteria and irrigation requirements of an AVF. The coal to be mined is located in the Paonia Coal Field. The rocks exposed in the Paonia Coal Field consist of the Marcos Shale and the coal-bearing Mesa Verde Formation of Upper Cretaceous Age, the Ohio Creek Conglomerate, the Wasatch Formation of Early Tertiary Age, and the Quartz monzonite porphyry of Tertiary Age. Coal is to be produced from the Mesa Verde Formation, 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 270 feet thick in the permit area and bears three minable coal seams. The member consists of interbedded sandstones, siltstones and coals, and is under- lain by the Rollins Sandstone. A massive sandstone 25 to 225 feet thick over- lies 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. Three categories of potential aquifers exist in the general area: Alluvial and terrace deposits associated with the North Fork of the Gunnison River and Sylvester Gulch to the east; lenticular, discontinuous sandstones and coals; and the Rollins Sandstone. Local bedrock ground water movement above the