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<br />Reconnaissance Survey on the Rockcastle Mine <br />August 27, 1980 <br />The present use of the land included in the lease area (besides <br />mining) is livestock and big game grazing and apparently this is the best <br />use of this land because the terrain is frequently dissected by natural <br />drainages. <br />There are three well defined vegetation types on the Rockcastle <br />lease that will be disturbed by coal mining. They are presented on the <br />Vegetation Map showing the leased area, the areas that have been disturbed <br />and those to be disturbed in future mining. The three vegetation types <br />involved include: (1) aspen; (2) mountain brush; and (3) sagebrush-grass. <br />The aspen areas occur mainly on the north and east aspects that <br />• vary from 5 percent to as much as 45 percent slope. The average foliage <br />cover to a 60 inch height was about 67 percent of which 32 percent was grass, <br />33 percent forbs, and 35 percent shrubs (Table 1). Much of this vegetation <br />type has down timber that would seriously restrict grazing. <br />The total dry matter herbage yield was estimated at 750 pounds per <br />acre with 525 pounds of usable forage if all the land were only moderately <br />sloping and the down timber was no problem. As a result of down timber and <br />rough terrain only 262 pounds of forage per acre was determined as usable <br />under practical grazing practices. This calculates to 3.63 acres per animal <br />unit month (950# per AUM _ 262 = 3.63) for the entire area of aspen that <br />will eventually undergo disturbance. <br />The aspen range area was considered to be in good range condition <br />and in more or less stable trend. Thus, it appears the area has not been <br />abused by livestock grazing in the past. <br />• The mountain brush areas occur mainly on south and west aspects that <br />vary in steepness from 3 percent to as much as 50 percent and as expected <br />II.A-3 <br />