Four active mine areas at the Rosebud Mine operate: Area A; Area B; Area C; and Area F. The Rosebud Mine is located in the northwestern portion of the Powder River structural basin, a broad northeast-trending synclinal structural basin in eastern Wyoming and southeastern Montana bound on three sides by mountain uplifts. The Paleocene Fort Union Formation is the predominant bedrock unit in the vicinity of the Rosebud Mine and consists of gently dipping (less than a few degrees) sedimentary rocks. Coal is within the Tongue River Member of the Fort Union Formation. The highest coal bed in the analysis area stratigraphic sequence is the Rosebud Coal bed, which averages 22.6 feet thick over the permit area. The next coal seam located below the Rosebud Coal bed is the McKay Coal bed, which averages 7.9 feet thick. Rosebud Mine Area B lies within the East Fork Armells Creek and Middle Rosebud Creek drainage basins. In the Colstrip area, the Fort Union Formation is 445 feet thick and thickens to the south to a maximum of 2,125 feet. Geologic formations that are exposed at the surface are limited to the Tongue River Member of the Paleocene Fort Union Formation, and Quaternary Alluvium. Quaternary-age alluvium and colluvium overlie the Tongue River Member locally, mostly along drainageways. Within the analysis area, relatively thin deposits of silty clay and gravelly sand comprise the Quaternary alluvial fill occurring within portions of Richard Coulee. Thin unmapped unconsolidated a ........

The mine is located near Colstrip, Montana. Overburden is removed exposing the Rosebud coal seam utilizing four draglines and is deposited in previously mined pit areas. The coal is loaded by front-end loaders into 100 ton and 200 ton haul trucks for transport to areas where the 2 coal is stockpiled. The coal seam averages 20 to 25 feet in thickness and overburden thicknesses vary from 20 feet to more than 200 feet.

Rosebud is a large operation with three active pits and supplies almost all of its current production to the four-unit 2,100 megawatt Colstrip Power Station that is adjacent to the mine and was specifically designed to burn Rosebud coal.

Number of Draglines Removing Overburden - 4.

The Rosebud Mine Area F expansion project is located 12 miles west of Colstrip, Montana, in Rosebud and Treasure counties. The Area F project would expand the Rosebud Mine, which currently is a 25,576-acre surface coal mine producing low-sulfur subbituminous coal.

The coal mining method proposed would be the same area strip mining method that currently uses in other permitted areas of the Rosebud Mine. In advance of each mining pass, soil would be removed from the area and stockpiled according to type for use later during reclamation. Next, the overburden (sedimentary rock material covering the coal seams) would be drilled and blasted. Overburden from the initial cut would be stockpiled as spoil. A dragline would then be used to strip the over ........

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