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• <br />-12- <br />Description of the Environment <br />The mine site is located in a plateau area. The elevation of the surface <br />facilities range from 7,400 to 7,800 feet. land use in the area consists of <br />cropland, rangeland and pastureland, and wildlife habitat. Agriculture is <br />practiced in the river valley and usually consists of hay production, Cattle <br />are grazed in the area year round, A large number of large and small mammals, <br />birds, fish and amphibians, and reptiies are permanent or temporary residents <br />of the area. Of special concern are Golden Eagles which breed and winter in <br />this area. <br />The AiTen Mine is located in the western limb of the Raton Basin. The Raton <br />Basin is abroad, asymmetric syncline whose axis trends north-south. All <br />mining activities occur in the Raton Formation where the Allen Seam is the <br />coal seam being mined. The Poison Canyon Formation unconformably overlies the <br />Raton. The Poison Canyon Formation has a thickness of approximately 200 feet <br />and occurs only as small isolated outcrops above an elevation of 8,000 feet. <br />Unconsolidated quarternary alluvial and colluvial deposits overlie the Raton <br />Formation in the low lying areas. ' <br />The rock strata dip approximately 2 degrees to the east-northeast. The permit <br />area contains one steep, normal fault trending east-northeast with vertical <br />displacement less than 25 feet. <br />The Allen Seam lies from 450 to 900 feet below the surface. Immediately above <br />the coal are interbedded sandstone and siltstone shales. Interbedded <br />sandstones, shales, and siltstones also underlie the seam. <br />Surface facilities for the mine are situated on both banks of the Middle Fork <br />of the Purgatoire River. Underground workings originate along the south bank <br />of the river and extend approximately 7,500 feet north under the river and <br />13,000 ft. south. <br />The alluvium of the Middle Fork of the Purgatoire River is a significant <br />aquifer in the permit and adjacent areas. <br />The Purgatoire River originates several miles west of the mine in the Sangre <br />de Cristo Mountain Range. It flows into the Arkansas River near Las Animas, <br />Colorado, approximately 120 miles northeast of the mine. <br />Portions of the Apache Canyon, Pete Canyon, and Ciruela Canyon drainages are <br />found within the permit area. These basins contain intermittent and ephemeral <br />streams which flow predominately in response to runoff from snowmelt during <br />the spring and intense rainfall during the summer. A portion of the flow in <br />intermittent drainages is sustained by ground water discharges. All these <br />streams are tributary to the Purgatoire River system. Pete Canyon is <br />tributary to the North Fork while Apache and Ciruela Canyons are tributary to <br />the main stem of the Purgatoire River. <br />The region is characterized by a semiarid climate. The prevailing wind is <br />from the southwest and average annual precipitation is 16.92 inches. The <br />length of the growing season in the area varies from 90 to 110 days. <br />