2010-12-27_REVISION - C1981019 (3)

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Field sampling for the directly measurable variable of ground cover was systematically conducted from July 27 through August 2, 2007. The growing season prior to and during the sampling period could be qualitatively characterized as above average with regard to recent year's precipitation. Sampling occurred immediately following the peak of growth in July. Field efforts in 2007 were conducted by or under the direct supervision of, Cedar Creek's Senior Range Ecologist, Mr. Steven R. Viert, Senior Plant Ecologist, Mr. Erik M. Mohr, and /or Range Ecologist. Mr. Jesse H. Dillon. The remainder of this document is divided into logical sections. Raw data tables are presented in Appendix A. Acreages presented in this document are determined by Colowyo's engineering and /or permitting department. Precipitation data presented on Table P and Chart P is the average of two weather stations at the Colowyo Mine (SCN16 and WSTPT). Precipitation in the project area was determined to be above average when compared with the seven -year average for the 2006 / 2007 growing season (September 2006 through August 2007). However, this seven -year average is potentially below the actual long -term average for the mine given that 2001 through 2004 are recognized as below- average precipitation years region wide (drought years). For example, the nearest official weather station (Craig 4SW) received only 44% of its average precipitation in 2001, 61% in 2002, 86% in 2003, and 83% in 2004. Given this analysis the long -term average precipitation at the Colowyo mine is most likely in the 19 inch range as opposed to the recent seven -year average of 17.14 inches. Therefore, precipitation during the 2006 / 2007 growing season (20.46 inches) was most likely only somewhat above average as opposed to well above average. Precipitation during the growing season was about average with April, May, and June exhibiting 0.92, 1.67, and 0.30 inches, respectively. CEDAR CREEK ASSOCIATES, Inc. Page 2 Colowyo Coal Company 2007 Phase II Evaluation (Updated Dec -10)