2010-12-27_REVISION - C1981019 (4)

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2.0 METHODOLOGY FOR VEGETATION SAMPLING / COMPARISON — COLOWYO MINE 2.1 Sample Site Selection / Location The sample layout protocol for revegetation evaluations in 2008 largely followed CDRMS approved procedures developed by Cedar Creek to provide unbiased, representative, and cost - effective data for evaluation of revegetation. These procedures are designed to better account for the heterogeneous expression of vegetation within the various reclaimed areas while precluding bias in the sample site selection process. By design, the procedure is initiated randomly, and thereafter, samples are located in a systematic manner, along grid coordinates spaced at fixed distances, e.g. 200 ft. (see Figure 1 and /or Maps 1 - 3). In this manner, "representation" from across the entire reclaimed area is 'forced" rather than risking the chance that significant pockets (or seedings) are entirely missed, or overemphasized as often happens with simple random sampling. The systematic procedure for sample location in the revegetated units occurred in the following stepwise manner. First, a fixed point of reference was selected for the unit to facilitate location of the systematic grid in the field. Second, a systematic grid of appropriate dimensions was selected to provide a reasonable number of coordinate intersections (e.g., 20) that could then be used for the set of sample sites (Phase II sampling used two grids for the purpose of stream - lining data collection, one grid was established for units that were also being sampled for Phase III release, a second grid was established for the remaining units). Third, a scaled representation of the grid was overlain on a computer - generated map of the target area extending along north /south and east/west lines. Fourth, the initial placement of this grid was implemented by selection of two random numbers (an X and Y distance) to be used for locating the first coordinate from the fixed point of reference, thereby making the effort unbiased. Fifth, where an excess number of potential sample points (grid intersections) was indicated by overlain maps, the excess were randomly chosen for elimination. (If later determined that additional samples would be needed, the eliminated potential sample sites would be added back in reverse order until enough samples could be collected.) Sixth, utilizing a handheld compass (or GPS) and pacing techniques (or a hip- chain), the sample points were located in the field. Once a selected grid point was located in the field, ground cover sampling transects were always oriented in the direction of the next site to be physically sampled to further limit any potential bias while facilitating sampling efficiency. This orientation protocol follows that which is indicated on Figure 1. Depending on logistics, timing, and access points to the target sampling area, the field crew would occasionally layout a set of points along coordinates in one direction and then sample them in reverse CEDAR CREEK ASSOCIATES, Inc. Page 4 Colowyo Coal Company 2008 Phase II Evaluation (Updated Dec -10)