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to facilitate an evaluation of success for reclaimed units. Because of the way these reference areas were <br />established during the baseline periods (both 1991 and 1992), a statistically valid "weighting procedure" <br />could not be developed that would have allowed Mine Area No. 1 and Mine Area No. 3 to be sampled <br />together as a combined unit. The Colorado Division of Reclamation, Mining, and Safety (CDRMS) <br />suggested that, in lieu of such a weighted assessment, comparison could be made to only the "strongest" <br />of the three reference areas. Though potentially viable, this procedure has two downsides. First, <br />comparison to only one reference area would require a Technical Revision to the permit. Second, and <br />more important, review of the expressed vegetation in the field by Cedar Creek personnel suggested that <br />such a comparison would present elevated potential for failure for Mine Area No. 3. Given these <br />circumstances, Cedar Creek determined it most prudent to sample each area independently and compare <br />each mine area to its original set of reference areas (currently permitted procedure). In this regard, Mine <br />Area No. 1 compares with Sagebrush Reference Area A (89% weight) and the Grassland Reference Area <br />(11% weight). Weighted values are based on pre- disturbance community acreages. Mine Area No. 3 <br />compares with Sagebrush Reference Area A (50% weight) and Sagebrush Reference Area B (50% <br />weight). No data or methodology could be found within permitting documentation to suggest any other <br />weighting scenario. Furthermore, the pre - disturbance footprint of Mine Area No. 3 was overwhelmingly <br />dominated by the sagebrush community. No grassland was present. <br />Field sampling for the directly measurable variables of ground cover, current annual production, and <br />woody plant density was systematically conducted from July 17 through July 21, 2010 and August 2 <br />through August 4, 2011 excepting that woody plant density was not collected in 2011. Woody plant <br />density is not required for bond relinquishment at the Hamilton Mine, but was collected to address any <br />possible concerns by the Colorado Division of Wildlife regarding wildlife habitat considerations. Sampling <br />occurred immediately following the peak of growth in July, and was conducted by, or directly under the <br />supervision of, Cedar Creek's Senior Range Ecologist, Mr. Steven R. Viert. Mr. Viert was assisted by Mr. <br />Jesse H. Dillon, Cedar Creek Range Ecologist, and a summer technician. In 2010, Mine Area 1 received <br />25 ground cover transects and woody plant density belts, and 50 production quadrats. In 2011 Mine <br />Area 1 received 24 ground cover transects and 48 production quadrats. In 2010, Mine Area 3 received <br />25 ground cover transects and woody plant density belts, and 50 production quadrats. In 2011, Mine <br />Area 3 received 25 ground cover transects and 50 production quadrats. All three reference areas were <br />sampled with 15 ground cover transects and 45 production quadrats in both 2010 and 2011. The <br />grassland reference area was split into two segments by the original baseline investigators (north and <br />* Digitizing an overlay of the baseline vegetation map against the disturbance footprint revealed 11% of the <br />disturbance acreage to have been originally mapped as grassland and 89% mapped as sagebrush or Pinon- Juniper <br />Woodland. At the time of permit development, P -J Woodland acreage was combined with the Sagebrush Community <br />for reclamation plan development as P -J was determined unnecessary/inappropriate for the post- mining land use. <br />CEDAR CREEK ASSOCIATES, Inc. <br />Page 3 Hamilton Mine - 2011 <br />Phase III Bond Release Evaluation <br />