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Ground cover of the four formally designated reference areas ranged from 19.0% - 25.0% live • <br />vegetation, 0.2% - 7.6% rock, 22.6% - 34.4% litter, and bare soil exposure of 38.2% - 54.6% (Table 2). <br />Perennial cover across the four areas ranged from 17.2% — 24.42% with annual and biennial cover <br />ranging from 0% — 1.8 %. Dominant taxa were again: Wyoming big sagebrush, blue grama, and needle <br />and thread. <br />3.4 Recommendations <br />As indicated previously, it is Cedar Creek's recommendation that the Hamilton Mine be sampled for <br />bond and liability release beginning in 2010 and continuing into 2011 with submission of documentation <br />to CDRMS to follow thereafter. Based on permitting documents, the entire disturbance area should be <br />sampled as a single unit. Furthermore, given the observed variability, it is recommended that 30 ground <br />cover and 60 production plots (minimum) be distributed systematically across the reclaimed surfaces if <br />standard "null" testing is to occur. If "reverse null" testing can occur, a somewhat reduced effort for <br />production would be appropriate (however, Cedar Creek would recommend a minimum of 45 samples in <br />this regard). <br />Similarly, the two grassland reference areas should be sampled as two separate segments of a <br />single unit (i.e. the number of needed samples should be proportionately distributed among the two <br />areas). In this regard, the number of samples should be 20 cover transects and 40 production (0.5m x <br />2.0m) quadrats (minimum). To the contrary, the two sagebrush reference areas (north and south or "a" <br />and "b') must be sampled as unique (segregate) units, each to their own level of adequacy (20 cover and <br />40 production for each, as a minimum). This is due to their establishment and verification during 1991 <br />and 1992, respectively. Subsequently, sagebrush reference area data will be combined (assume a 50/50 <br />weighting) for use in a weighted evaluation (with the grassland reference area) for comparison against <br />the reclaimed area for the variables of ground cover and current annual production. Diversity <br />comparisons will be against the aforementioned standards based on a simple transformation of the <br />ground cover data to "composition ". Woody plant density is not a required standard, however, Cedar <br />Creek would recommend that co- located 2m x 50m density belts be run concurrently with reclaimed area <br />ground cover transects for informational purposes (to satisfy any Colorado Division of Wildlife concerns). <br />Also, as indicated above, it is Cedar Creek's recommendation that an aggressive program of Russian <br />knapweed control (as well as any other noxious weeds observed in the area) be maintained over the <br />course of the next two years, along with follow -up maintenance -level control for three additional years. <br />This follow -up maintenance should, however, be the land- owner's responsibility (assuming full control of <br />knapweed populations has been attained prior to bond release). <br />0 <br />CEDAR CREEK ASSOCIATES, Inc. Page 9 Hamilton Mine - Revegetation Evaluation - 2009 <br />