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coal are interbedded sandstone, siltstone, and shales. Interbedded sandstones, shales, and <br />siltstones also underlie the seam. <br />The alluvium of the Middle Fork of the Purgatoire River is a significant aquifer in the permit <br />and adjacent areas. The Purgatoire River originates several miles west of the mine in the <br />Sangre 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 found within <br />the permit area. These basins contain intermittent and ephemeral streams that flow <br />predominately in response to runoff from snowmelt during the spring and intense rainfall <br />during the summer. A portion of the flow in intermittent drainages is sustained by groundwater <br />discharges. Pete Canyon is tributary to the North Fork, while Apache and Ciruela Canyons <br />are tributary to the main stem of the Purgatoire River. <br />The region is characterized by a semi-arid climate. The prevailing wind is from the southwest <br />and average annual precipitation is 16.92 inches. The length of the growing season in the <br />area varies from 90 to 110 days. <br />Vegetative communities in the area of the mine can be separated into two physiognomic <br />types; the low grassland and riparian communities along the Purgatoire River valley bottom, <br />and forest communities dominating the slopes and upland areas along the river valley. <br />Communities on the north-facing slope and the river valley were inventoried and found to <br />contain four distinct vegetative communities at the New Elk Mine area; a Ponderosa pine- <br />Douglas fir-oak community, a Ponderosa pine-oak community, a grassland community, and a <br />riparian willow carr community. The Ponderosa pine-Douglas fir-oak community is found on <br />the north-facing slope above the mine facilities at elevations above 7,600 feet. The overstory <br />consists of mature Ponderosa pine and Douglas fir with interspersed pinon pine and Rocky <br />Mountain juniper. The dominant shrub species is Gambel's oak. Cover is relatively sparse <br />(12 percent) and productivity is low (62 lb./ac). The Ponderosa pine-oak community occurs on <br />the north facing slopes above 7,500 feet on the eastern two-thirds of the permit area. Pure <br />Ponderosa pine stands are interspersed with Gambel's oak, pinion pine, and Rocky Mountain <br />juniper. Vegetative cover is low (4 percent), as is productivity (44 lb./ac). The grassland <br />community was inventoried at the adjacent Golden Eagle Mine on a plateau above the river at <br />7,200 feet elevation, since no undisturbed grassland communities could be found at the New <br />Elk Mine. Dominant grass species were blue grama and western wheatgrass, with many other <br />minor graminoids including a number of forbs. Sage and snakeweed were the dominant <br />shrubs. Vegetative cover can be characterized as moderate (18 percent), as is productivity <br />(560 lb./ac). The willow carr riparian community is located in the Purgatoire River drainage at <br />an elevation of 7,400 feet at the New Elk Mine. The dominant species was willow with a <br />diverse graminoid and forb understory. Vegetative cover is high (43 percent), as is productivity <br />(2,140 lb./ac). <br />Soils in the area range from very shallow on the steep side slopes to deep, well-drained loams <br />with a dark-colored surface layer found in the valley bottom along the Purgatoire River. <br />5