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through J. Deserado Mine's zone of interest is the B -Seam located in the Lower Williams Fork Formation of the Mesaverde Group. Although there are several smaller coal seams, the B -Seam is the only mineable in the proposed LBA. It is divided into two separate splits, the Upper and the Lower B -Seam with a parting that ranges from 1 to 3 feet. The estimated coal reserve base is approximately 27 million tons (both splits of the B -Seam) and the estimated mineable reserve is 21.3 million tons (lower B- Seam). The majority of mining is projected to occur in the lower B- Seam. The LBA is located in an area identified in the 1997 White River ROD /RMP as acceptable for further consideration for coal leasing and as having high potential for oil and gas occurrence. An isolated 40 acre parcel of Federal oil and gas lease COC73884 encumbers the NWNW, Section 21, Township 3 North, Range 101 West, 6th Principal Meridian of the LBA. No producing or abandoned oil and gas wells are within the LBA according to the Colorado Oil and Gas Conservation Commission (COGCC) database. A mining claim for locatable minerals adjoins the LBA on the northern border of the NE Section 20, Township 3 North, Range 101 West 6"' Principal Meridian. Environmental Consequences of the Proposed Action: Direct and Indirect Effects: The Deserado Mine Plan predicts maximum subsidence ranging from 4.2 feet to 7.7 feet in the longwall panels. The amount of subsidence is determined by the depth of overburden and the height of the coal seam mined. Typically, shallow overburden and higher mining height create greater surface expression of subsidence. Results from monitoring of surface subsidence from longwall mining at the Deserado Mine are below the predicted maximum vertical subsidence. Ninety -five to 98 percent of the subsidence resulting from longwall mining occurs during active mining. Long -term subsidence hazards are not expected with longwall mining since such hazards are manifested in a fairly short time. Subsidence above previously mined longwall panels along Rio Blanco County (RBC) roads 65 and 96 and the mine's power line has not interfered with usage of the roads or power line. BME's approved Deserado Mine Plan contains subsidence monitoring and mitigation. Quarterly subsidence reports are submitted to the Division of Reclamation Mining and Safety. Areas and structures that could be affected by subsidence include tributaries to Red Wash, RBC roads 65 and 73, Moffat County (MC) Road 61, clean coal slot storage, rail load out, associated power lines, and coal refuse disposal area. Given the past experience with subsidence at the mine site, subsidence is not expected to adversely affect these areas or structures. Removal of the LBA coal would deplete the underground B -Seam recoverable resources and allow the maximum economic recovery of the underground coal resources in the LBA and the Deserado Mine area. MSHA regulations requires a coal barrier of not less than 300 feet in diameter around oil and gas wells which could limit the recovery of coal resources in the 40 acre parcel of oil and gas lease COC73884. However, it is unlikely mining would occur below the majority of parcel of COC73884 due to the increase in thickness of the partings within the B- Seam. Leasing and developing the coal resources would have little to no effect on the mining claims north of the LBA. Cumulative Effects: Cumulative effects of longwall subsidence would be minimal to the geologic and mineral resources in the Red Wash and Scullion Gulch watersheds. DOI- BLM -CO- 110 - 2012 - 0023 -EA 34