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-5- The drainage basin of the North Fork is mountainous, bounded, to the west by the Ragyeds, the Ruby Ranye; to the east by the Huntsman Ridye, to the South by the West clk Mountains, and to the north by Grand Mesa. Elevations in the basin range from 13,U58 feet atop Mt. Owen in the Ruby Kanye to 5,1OU feet at the confluence of the North Fork with the Gunnison River. The town of Somerset, Colorado immediately adjacent to the Somerset mine site is at an elevation of b,U45 feet. U.S. Steel has identified only one spriny in the pe rnrit and adjacent areas. This spring is located on Elk Creek. A search of the State Engineers records was conducted to find any additional adjudicated springs. No sprinys were found in the permit or adjacent areas. The Elk spriny has a flow rate of less than one yallon per minute. . The topography of the region is characterized by steep canyons rut by the North Fork and its tributaries, with several remnant alluvial terraces above the valley of the North Fork. As one proceeds downstream below Somerset, Colorado, the canyon widens. At Paonia, Colorado the canyon has yiven way to a broad alluvial plain with interspersed remnant alluvial terraces. The coal to be mined is located in the Somerset Coal Field. The rocks exposed in the Somerset Coal Field consist of the t4ancos Shale and the coal-bearing tesaverde Formation of Upper Cretaceous Aye; and the Ohio Creek Conglomerate, the Wasatch Fo rnration and the t?uartz monzonite porphyry of Early Tertiary Aye. (See Stratigraphic Cross Section, Figure 3 of this document). Coal is to be produced from the Mesaverde Formation, a 2,50U foot thick sequence of sedimentary strata overlain by the Uhio Creek Conglomerate and underlain by the Mancos Shale. Beds exposed in the Somerset Permit area dip 3-5 degrees north-northeast. Tn~ Mesaverde Formation contains two coal bearing members.lhe Somerset Mine will extract coal from the "d-2" sewn of the Lower coal bearing (Bowie) member of the Mesaverde Formation. The Lower Coal member ranges fruin 200 - 350 feet thick in the Somerset Coal Field and bears three minable coal seams. The member consists of interbedded and lenticular sandstones, siltstones and coals, and is overlain by a massive sandstone 25 to 225 feet thick which overlies the "C" seam and marks the bottom of the Upper Coal Member. Three cateyories of potential aquifers exist in the general area: alluvial deposits associated with the North Fork of the Gunnison River and its tributaries; the kollins sandstone; and lenticular, discontinuous sandstones of the Upper Mesaverde Formation. The laryest alluvial aquifers are associated with the North Fork df the Gunnison River. Smaller, more isolated alluvial aquifers are associated with several of the tributaries of the North Fork. The Rollins sandstone is the only known sandstone witty sufficient porosity and lateral extent to be considered a regional bedrock aquifer. The only wells in the reyion which are completed in this aquifer are located near the Hawk's Nest Cline along the North Fork .