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The pre-law trommel screen reject contained a significant <br /> percentage of coal, therefore, this slope is the least vegetated <br /> and contains gullies that continue unbroken from the top of the <br /> slope to the bottom. Screening operations ceased prior to 1977 . <br /> The spoil slope extends from the portal bench to a point <br /> approximately 450 feet below. The enclosed photo shows the <br /> downslope area in detail. The overall grade is roughly 1. OH: 1. OV. <br /> Approximately 16 gullies exist ranging in depth from 2 feet to 7 <br /> feet. A crust has built up on the surface of the slope over the <br /> years which is helpful in controlling erosion. Close site <br /> inspection reveals no evidence of significant recent (last five <br /> years) erosion. Most of the gullies have reached a relative <br /> equilibrium and are not expected to produce significant erosion <br /> during normal runoff events. <br /> 3) Mine #1 <br /> Mine 11 contains two significant and two minor pre-law spoil <br /> slopes created when the portal bench was excavated. The enclosed <br /> photo shows the 2 southernmost downslope areas in detail. These <br /> are the two significant slopes. The natural slope located to the <br /> left of the spoil slope looks very similar to the disturbed slope <br /> and it .also contains little vegetation. The enclosed map section <br /> shows all four downslope areas. The slope material consists of <br /> Mancos Shale, weathered coal from the seam outcrop and some <br /> sandstone material from minor beds excavated above the coal seam. <br /> The spoil slopes in the photo extend from the portal bench to a <br /> point approximately 400 feet below. The overall grade is roughly <br /> 1.OH: 1.OV. Although some clump grasses have been established <br /> naturally on the slope, very little vegetative cover exists. <br /> Approximately 30 gullies of depths greater than 3 feet exist, with <br /> lengths greater than 100 feet. A few gullies exist over 8 feet in <br /> depth, however, for the most part, the gully depths do not exceed <br /> 5 feet. The two southernmost downslope areas are located directly <br /> in avalanche paths and have been difficult to naturally vegetate. <br /> Due to the avalanche paths and heavy snowfall, these slopes are <br /> more active than the others in the area and the protective crust <br /> which exists at the other areas is not as prevalent on the slopes <br /> at Mine 11. <br /> The two minor downslope areas to the north are less than 150 <br /> feet in length. The slopes are milder, approximately 1. 3H: 1. OV and <br /> gullies in excess of 2 feet are rare. Clump grasses also exist on <br /> these slopes but no appreciable vegetative cover exists. <br />