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Colowyo C-1981-019 <br />10 February 2010 <br />Pg 3/4 <br />Excess Spoil: - The C-C' underdrain area of the East Taylor Fill is not currently being <br />used as a dump. Colowyo is currently dumping overburden material in the Section <br />16 Pit and the West Taylor Fill (the A-A' and B-B' underdrain areas). The East Taylor Fill <br />has progressed to fifth lift and is currently above the post-mining topography <br />(Colowyo is now working on the temporary stockpile portion of the pile). Colowyo <br />will use this temporary overburden stockpile as backf ill for the South Taylor Pit and <br />plans to return all of the material above the approved final topography to the South <br />Taylor Pit. <br />- Colowyo is currently working on the second lift of the B-B' and A-A' underdrain <br />areas of the West Taylor Fill. The fill is being pushed out from the confluence area (of <br />the A-A' and B-B' underdrain area) towards the toe of the fill. Once Colowyo has <br />pushed out the material to the toe area of the West Taylor Fill they will work back up <br />the valley along the A-A' underdrain. <br />OSM AOC SPECIAL FOCUS INSPECTION: - The main inspection topic on the 10 <br />February 2010 inspection was the approximate original contour of the backfilled and <br />graded areas at the Colowyo Mine. The OSM conducted an office review of the <br />permit (including all appropriate text and maps) to determine compliance with the <br />AOC Rules and they chose Colowyo as one of the sites to do a field visit to determine <br />whether the AOC was being achieved on the ground. A portion of the East Pit <br />reclamation (approximately 700 acres) was walked and 33 elevation points were <br />taken. The elevation points were taken with a Trimble GeoXT handheld unit. All <br />elevation measurements with the Trimble GeoXt are relative, as they were not based <br />on a known control point. The elevations were compared with the approved post- <br />mining topography from Map 19 and seven cross-sections were plotted (see <br />attached cross-sections). The following chart is a summary of the overall elevation <br />changes and grades for the seven cross-sections: <br /> <br />Section <br />Elev Chng <br />Grade PMT <br />Chng PMT <br />Grade <br />A-A' 29.6 4.69% 30.0 4.75% <br />B-B' 18.6 1.33% 35.0 2.49% <br />C-C' 43.7 2.89% 50.0 3.31% <br />D-D' 137.7 6.17% 175.0 7.85% <br />E-E' -5.2 -0.60% -5.0 -0.58% <br />F-F' -15.0 -1.19% -70.0 -5.56% <br />G-G' 85.7 5.24% 90.0 5.50% <br />The cross-sections and all raw data for the elevation points are attached at the end <br />of this report. In all but one case there appears to be good correlation between the <br />relative grades for the approved post-mining topography and the measured grades. <br />In one instance the measured grade was several percent less steep than the PMT <br />grade (cross-section F-F').