2014-10-10_REVISION - C1996083 (5)

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Three sites within the Spruce Stomp lease area have been deemed eligible for listing on the National Register of Historic Places by the State Historic Preservation Officer. No surface disturbance is proposed under this permit revision, and the applicant has predicted that the three sites will not be affected by subsidence. Section 2.05.6(4) of the permit application package includes a discussion of the sites and the determination that the sites will not be negatively affected by mining. Since the determination of no effect is based on the assumption that there will be no surface disturbance within the Spruce Stomp lease area, the following stipulation is placed on the proposed decision to approve PR -14: PRIOR TO ANY SURFACE DISTURBANCE OF LANDS WITHIN THE SPRUCE STOMP LEASE AREA (COC- 75916), BRL WILL NEED TO EVALUATE THE EFFECTS OF THAT DISTURBANCE ON ANY OF THE SITES LISTED AS ELIGIBLE FOR LISTING ON THE NATIONAL REGISTER OF HISTORIC PLACES, AS DOCUMENTED IN THE 2012 CLASS III CULTURAL RESOURCES INVENTORY REPORT FOR THE LEASE AREA. Geology Detailed information regarding the geology in and adjacent to the Bowie No. 2 Mine permit area is provided in Sections 2.04.5 and 2.04.6 of the permit application document. A brief summary is provided below, and this summary is derived from the information presented within Sections 2.04.5 and 2.04.6 of the permit application. The Bowie No. 2 Mine permit area is located in the North Fork Valley of the Gunnison River, near the western margin of the Colorado portion of the Central Rocky Mountains. The elevation of the permit area ranges from about 6,000 feet above sea level to over 8,000 feet above sea level. The general area is situated along the southern flank of the Piceance Creek structural and sedimentary basin. The area is bounded by Larimide structural and physiographic features on the following sides: West Elk and Elk Mountains on the east; the Gunnison Uplift on the south; the Uncompahgre Uplift on the west - southwest; and the Grand Mesa- Piceance Basin on the north. The geologic structure of the permit area exhibits an attitude of N66 °W, with a 3 to 5- degree dip to the northeast. There is one identified fault located in the southwest corner of the permit area. The fault trends approximately N55 °W and it dips 70 to 80 degrees to the northeast. The throw of the fault ranges from 7 to 30 feet, with the downside located on the south side of the fault. The coal in the area is situated within the Mesaverde formation which contains interbedded sandstones, mudstones, shales, siltstones and coal beds. The Mesaverde formation lies upon the Rollins Sandstone Member of the Iles formation and below the Wasatch formation. The coal - bearing member of the Mesaverde formation locally contains up to nine (9) coal seams. These seams are located within a stratigraphic interval of approximately 500 to 600 feet above the Rollins Sandstone. These coal seams are, in ascending order, the A -Seam, the B -1 Seam, the B -2 Seam, the C -Seam, the D -1 Seam, the D -2 Seam, the E -1 Seam, the E -2 Seam and the F -Seam. The B -2 and D -2 Seams are mineable within the permit area. The D -2 Seam overlies the Rollins Sandstone by 350 to 450 feet, and it ranges in thickness from about 8 to 16 feet. The B -2 coal Page 16 of 46