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III. Description of the Environment <br /> A. General and Affected Area <br /> The New Horizon Mine 1 permit block encompassed approximately 98.6 acres that have been <br /> reclaimed. This area is commonly referred to as the Rice tract. Revegetation sampling was <br /> initiated on this tract in 2006 and the initial results indicated that it would not achieve the Phase <br /> III revegetation success standards. On June 20, 2012, the Mine 1 area was incorporated into the <br /> New Horizon North Mine (Permit No. C-2010-089), which is also operated by ERMR. <br /> The New Horizon Mine 2 permit block encompassed approximately 818.19 acres. Approximately <br /> 736.6 acres was disturbed for mining or related activities. The majority of this findings document <br /> pertains to the remaining Mine 2 area, since the activities at Mine 1 are documented in the New <br /> Horizon North permit, C2010-089. <br /> The topography is gently sloping with a few small ridges and swales. Most of the land surrounding <br /> the permit area is agricultural and is used for irrigated and non-irrigated farmland that generally <br /> produces alfalfa or pasture grasses. <br /> The mine is located within the southeastern portion of the Colorado Plateau. The region is <br /> characterized by broad and fairly smooth surfaced plateaus and mesas with gently dipping slopes <br /> which are dissected by steep canyons. Surface elevations at the New Horizon Mine 2 area range <br /> from a high of 5,795 feet (MSL) in the northeast part to a low of 5,555 feet in the northwest part <br /> along Tuttle Draw for a total relief of about 240 feet. <br /> B. Geology and Topography <br /> The New Horizon Mine is located near the axis of the Nucla Syncline (San Miguel Syncline), a <br /> shallow, broad synclinal fold running northwesterly for a length of 65 miles. No evidence of <br /> faulting was observed in drill holes at New Horizon Mine 2 area. The Nucla Syncline is 10 to 15 <br /> miles southwest of the major regional geologic feature of the area, the Uncompahgre uplift. The <br /> region lies in the Dolores River basin. The mine is located between two and three miles northeast <br /> of the San Miguel River. Gently rolling terrain traverses the area and the mine occupies a <br /> predominantly southwestern exposure. <br /> The mine is located in the Nucla-Naturita coal field. The coal is found in late Cretaceous <br /> sediments. The youngest Cretaceous rocks in the area are Mancos shale, a dark gray marine shale, <br /> comprising the isolated hilltops south of the town of Nucla. The Mancos shale overlies the Dakota <br /> sandstone. Two hundred feet of Dakota sandstone outcrops extensively along the axis of the Nucla <br /> syncline. This formation consists of a yellowish-gray, fissile sandstone and conglomeratic <br /> sandstone interbedded with dark gray shale and coal. There are two coal seams within 100 feet of <br /> the base of the Dakota. The lower Cretaceous unit in the area, the Burro Canyon Formation, is <br /> separated from the Dakota by an unconformity. The Burro Canyon is comprised of white, gray <br /> and light brown sandstones and conglomerates interbedded with green and purplish shales, <br /> siltstones, mudstones and thin beds of limestone. This formation has a maximum thickness of 200 <br /> feet and outcrops on rims of canyons west and northwest of the mine. The Burro Canyon formation <br /> 10 <br />