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• end of the project and gradually thickens to the west. The topsoil and overburden thickness is expected to range from 0 ft. to 20 ft. The topsoil is thinnest in the east in the West Property Line to Horse Fence and Slough to East Property Line Areas. The topsoil and overburden thicken to the west reaching depths of 2' to 18' in the West End Pit. The topsoil and overburden in the Dry Creek to Slough and West End Pits also increases in depth to the south along the CDOT ROW. The topsoil is comprised of Torrifluvents and Halaquepts over most of the mining area. The Torrifluvents have a surface layer that ranges from loamy sand and fine sandy loan to a silty loam and clay loam. The underlying layers are generally sandy loam or loam stratified with sand, gravel and cobbles. The upper 24" of the Halaquepts soil ranges from loam to clay with underlying layers mostly gravel. In both soil areas gravel and cobbles aze at or near the surface. The estimated topsoil and overburden quantities by mining area are: Mining Area West End Pit Dry Creek to Slough Slough to East Property Line West Property Line to Horse Fence Total Quantity, cu. yd. 246,674 73,501 77,120 123,304 520,599 The estimated quantities of topsoil and overburden were modelled using LandDesign Desktop Civil Package. The topsoil and overburden depths from exploration pits and drill holes were used to develop a three dimensional model. An existing grade surface was developed from the topographic maps and a bottom of overburden surface was created using exploration data. Volumes were calculated using the following four methods: • Grid • Composite • Average End Area • Prismoidal The printout from the calculations are attached in Tables E-3-A, B, C, and D in Exhibit E - Reclamation Plan. The stratum under the sand and gravel is a shale. The primary commodity to be mined is sand and gravel. No secondary commodities are going to be mined. The intended use of the primary commodity is construction products.