2014-12-08_GENERAL DOCUMENTS - C1981044

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Townshin 6 North. Ranize 92 West Portions of S1 /2 Section 25; Sl /2 SEl /4 Section 26, Portions of E 1/2 Section 35; Portions of Section 36 Township 5 North, Range 92 West: E1 /2 NEl /4 Section 1. Regional Climate. The climate of the region is classified as highland continental, and is characterized by low precipitation, large fluctuations in diurnal temperatures, low humidity, moderate wind, and high levels of insolation (exposure to sunlight). The Craig area is in the rain /snow shadow of mountain ranges to the west and south and consequently has a high number of dry, clear days. Local Climate. The climate of the Craig, Colorado area is characteristic of semi -arid steppe regions. The average annual precipitation for the town of Craig, 6 miles northeast of the Williams Fork Mines, is 13.5 inches of which over one -third is snowfall (averaging 66.5 inches /year). Average annual precipitation at the Trapper Mine, next to the Williams Fork Mines, is 16.7 inches. The mean annual temperature in Craig is 43 F, with recorded extremes of -45�F and +100 F. Winds are predominantly from the west, but are locally modified by topographic features. The growing season for the area around Craig averages 77 days. Physiographic Setting. The No. 5 and No. 5A portals of the Williams Fork Mines are driven into the steep -sided walls of the valley that the Williams Fork River has cut through at the west end of the Williams Fork Mountains. The mines' facilities area is in the bottom of the valley. The elevation of the valley bottom is 6,150 ft. From the valley bottom, the permit area extends up to the crestal ridge of the Williams Fork Mountains. The crest of the Williams Fork Mountains forms a ridge extending about 30 miles east -west at elevations between 7,400 and 7,800 feet. The Williams Fork River crosses through the mine permit area and flows into the Yampa River in the northwest corner of the permit area. The Yampa River is one of the largest tributaries of the upper Colorado River system. Stratigraphic Setting. Bedrock at the ground surface in the Williams Fork Mines permit area is a sequence of sandstones, siltstones, shales, and coals that are part of the Cretaceous -age Williams Fork Formation. The Williams Fork Formation is part of the regionally extensive Mesa Verde Group. The Williams Fork Formation crops out along a six -mile wide belt that extends along the entire length of the Williams Fork Mountains. The Williams Fork Formation is subdivided into the following three units (in ascending stratigraphic order): the lower Williams Fork, the Twentymile sandstone, and the upper Williams Fork. Approximate thicknesses are: lower Williams Fork, 840 ft.; Twentymile sandstone, 120 ft.; and upper Williams Fork, 850 ft. Unconsolidated alluvial deposits of Quaternary age fill stream drainages in the permit area and surrounding areas. The alluvium is thickest in the Yampa and Williams Fork River valleys. Coal Seam Stratigraphy. The coal seams formally mined at the Williams Fork Mines are in the lower and upper units of the Williams Fork Formation. Each seam is less than 10 feet thick. The No. 9 Mine removed coal from the P seam in the upper Williams Fork Formation. The No. 5 Williams Fork Mines 5 Permit Renewal 06 C- 1981 -044 December 8, 2014