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five degrees north-northeast. <br />The Mesaverde Formation contains two coal bearing members. The Somerset Mine mined coal <br />from the B-2 seam of the lower coal beazing (Bowie) member of the Mesaverde Formation. The <br />Sanborn Creek and Sanborn Creek East additions to the mine will extract coal from the B and C <br />seams of this member. The Lower Coal member ranges from 260 to 350 feet thick In the <br />Somerset Coal Field and bears three minable coal seams. This member consists of interbedded <br />and lenticular sandstones, siltstones and coals, and is overlain by a massive sandstone 25 to 225 <br />feet thick which lies directly on the C seam and marks the bottom of the upper coal member. <br />Three categories of potential aquifers exist in the general area: alluvial deposits associated with <br />the North Fork of the Gunnison River and its tributaries, the Rollins Sandstone, and lenticular <br />discontinuous sandstones of the Upper Mesaverde Formation. <br />The largest alluvial aquifers are associated with the Noah Fork of the Gunnison River. Smaller, <br />more isolated alluvial aquifers are associated with several tributaries of the North Fork. <br />The Rollins Sandstone is the only known sandstone with sufficient porosity and lateral extent to <br />be considered a regional bedrock aquifer. The only wells in the region which are completed in <br />this aquifer are located near the Hawk's Nest Mine along the North Fork. <br />Localized perched bedrock aquifers exist in the discontinuous, lenticulaz, fine-grained sandstones <br />of the Upper Mesaverde Formation. The amount of ground water in these sandstones is <br />controlled by faulting and fracturing of the strata (secondary porosity) and the topography of the <br />recharge area. No known wells are completed in the sandstones of the Upper Mesaverde <br />Formation above the mine workings. <br />The valley in which the towns of Paonia and Somerset are situated is semi-arid, with annual <br />precipitation averaging about 15 inches per yeaz. Mean annual precipitation increases with <br />elevation, reaching over 40 inches per year near the summit of Mt. Owen. The May-September <br />precipitation is five inches for the lowlands and 13 inches for the mountain peaks. This indicates <br />that snowfall patterns play an important part in determining the hydrologic conditions of the area. <br />Temperature extremes at Paonia have ranged from -28°F in January to 100°F during July and <br />August. The average annual temperature is approximately 49°F. Snowfall averages 58 inches <br />per yeaz. <br />The general area in which the Sanborn Creek Mine is located is chazacterized by steeply sloping <br />mountains covered either with tall shrub vegetation dominated by oakbrush and servicebetry, or <br />stands of pinon and juniper trees. Drainages in the area are lined with riparian vegetation <br />communities along the stream banks. Some of the more level areas have been cleared and <br />support limited livestock grazing; however, for the most part, the surrounding land is <br />undeveloped and is used primarily as wildlife habitat. Recreational activities such as big game <br />hunting, trapping, fishing, and off-road driving also occur in the general area. <br />