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• Introduction <br />Phis report has been prepared for the Colorado Department of Mining and <br />Geology, DMG, in response to Stipulation 12 of Powderhorn Coal Company's, PHCC, <br />Mining and Reclamation Permit No. C - 81 - 041. This stipulation requires the <br />submission of an annual report detailing the results of PHCC's subsidence monitoring <br />inspections. This report contains descriptions of the local terrain, geology, mining <br />practices and details of the surface subsidence inspections. <br />Topoeranhv <br />PHCC operates the Roadside North and South Portals located 4 miles east of <br />Palisade Colorado. The surface terrain is typical for an arid mountainous region with <br />moderately sloping hills giving way to massive sandstone cliffs. Vegetation is limited <br />to various grasses, sagebrush, saltbrush, and a small population of pinyon junipers. <br />Geolos:v <br />In the near vicinity of the mine property the rock strata are composed of three <br />formations; the Mt. Garfield Formation, the Hunter Canyon Formation and the <br />Wasatch Formation. <br />• The most important formation is the Mt. Garfield Formation because it <br />contains three coal seams of economic significance. These seams are the Palisade, the <br />Cameo, and the Carbonera seams. <br />The Palisade Seam is 3 ft. to 4 ft. thick near the abandoned Midwest mine and <br />rapidly thins to the west, south and east. The Cameo Seam overlies the Palisade <br />Seam by 400 ft. to 450 ft. and is currently the only seam being mined in the <br />immediate area. The Cameo Seam ranges in thickness from less than 5 ft. to over <br />10 ft. and is the thickest in the north western parts of the property. The Carbonera <br />Seam overlies the Cameo Seam by 38 ft. to 93 ft. and is characteristically aseries of <br />detached seams rather than a single seam. The remaining 200 ft. to 400 ft. of the <br />Mt. Garfield Formation consists of interbedded to laminated carbonaceous silty, fine <br />to very fine grained sandstones and carbonaceous sandy siltstones. <br />Overlying the Mt. Garfield Formation is the Hunter Canyon Formation. It <br />consists of massive brown -buff and gray sandstones and soft gray shale and ranges <br />from 375 ft. in the west to 1,400 ft. in the east. <br />• Page 1 <br />