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1.0 Placer Gold Mine Plan <br />1.1 General Plan Gold Mining <br />Past mining history has shown that significant gold placer deposits are found in dips or depressions <br />in the bedrock within the permit area. Good concentrations can also be found in previous locations <br />of the South Platte River channel. Recent seismic testing of the exact bedrock location (2002) has <br />shown some dips and an older channel location near the west edge of the permit area. Based on this <br />testing and past operations, this area will be targeted for mining. The seismic cross - section locations <br />are shown On Map C -1 and Map C -2. The actual cross sections showing the bedrock as well as the <br />current surface are given in Appendix D. It is expected that 15 to 20 feet of overburden gravel will <br />be excavated and placed in previous pit excavations to get to the lower 5 -10 feet of gravel above the <br />bedrock, which is known to contain the high gold concentrations. In virgin areas, soil from 3" to 9" <br />is salvageable and will be stockpiled as shown on Map C -2. The expected average is 4.5" based on <br />existing cuts of the surface. <br />The areas will be mined in strips of approximately 300 feet long by 150 feet wide with 2H:1 V <br />sideslopes to get to the bedrock. These sequential cuts are labeled on the mine plan. Prior to any <br />mining for this amendment, a gravel berm of a minimum of 8' height, 2H:1 V sideslopes will be cre- <br />ated along the Highway 9 ROW for at least a 600' length around the active mining area. This will <br />visually shield the operation from the Highway, as well as minimize noise impacts. Dust should be <br />minimized since much of the mining will take place below the water table, therefore, the material to <br />be mined will be wet. Almost all of the gravel sent to the prep plant will be wet. <br />The operation will resemble a coal strip operation since dozers, loaders and trucks will be used to <br />move the overburden from the area to be mined to the adjacent previously mined area. While the <br />previous mined area is being graded, the lower portion of the gold - bearing gravel will be mined by <br />loader loading into a rock grizzly with 5" openings to ensure that only -5" material enters the porta- <br />ble 36" conveyor system, which will transport the material to the fixed plant location shown on Map <br />C -2. The initial 2 -3 cuts may utilize trucks to transport the gold - bearing gravel to the plant since <br />Alma Placer Mine 1115 12 <br />