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EXHIBIT D MINING PLAN <br /> 1. General Mining Plan <br /> The property boundary was surveyed and is staked on site; the new permit area will be surveyed <br /> prior to any site disturbance. Map C-1 shows the Current Conditions of the Garrett Pit. Mine <br /> access will be via 9 Rd from 125/Twelvemile Road accessed from CO-368 and CO-370 and <br /> Alamosa to the east, as it has been to this point. <br /> The gravel resource at the Garrett Pit is composed of a Quaternary gravel zone overlying <br /> Tertiary volcanics associated with the San Juan Mountains to the west. The gravel deposit is <br /> estimated to be approximately 40 feet thick and is overlain by very variably thick 0-5 inches to <br /> 12-18 inches of topsoil and variable thickness of overburden. The deposit rests on over 2,000 <br /> feet of Pleistocene alluvial fan deposits composed of the Alamosa Formation and the Santa Fe <br /> Formation deposited over> 8,000 feet of Tertiary volcanic and sedimentary deposits and <br /> Precambrian basement gneiss. Map C-1 shoes the Mining plan with projected north to south <br /> phasing and Map F-1 features the Reclamation plan. <br /> In general, the new mining phase will be mined by first excavating the variably thick topsoil and <br /> overburden with scrapers, front end loaders, and dump trucks. Limited topsoil is expected to be <br /> recovered and will be stockpiled when recoverable. Overburden is believed to have a maximum <br /> thickness of 6.5 feet thick and consists of variable compositions of sandy to cobbley to sandy <br /> clay loam of the Derrick and Graypoint soil profiles. While considered overburden, cobbles may <br /> be recovered from the above mentioned clastic loam units. Recoverable topsoil, overburden, and <br /> separated waste fines will be stockpiled and used to backfill mined out areas to a 3H:1 V slope <br /> during Reclamation, as shown on Map F-1. <br /> After overburden is removed, gravel mining will reach existing pit depths of approximately 25- <br /> 30 feet below the ground surface at a final median elevation of 7,740 feet. The maximum active <br /> highwall will be 20 feet tall and 300 feet long and may be composed of two 20 foot lifts. The <br /> Garrett Pit mines using two methods, 1) by excavating pit.material via track type dozers that <br /> push material down and toward loaders, and 2) by loader pick-up at the base of an active <br /> highwall. With both mining techniques, front-end loaders are used to transport material to <br /> portable plants. Therefore, the slope of pit walls mined using dozer-push down are less than or <br /> Garrett Pit Greg I ewicki aad Associrtes PI.1(' <br /> February 2018 D-1 <br />