2013-05-03_GENERAL DOCUMENTS - M1974004

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Martin Marietta Materials Spec -Agg 2013 Annual Report 4.0 MINING PLAN AND PROGRESS Mining activities have been focused in two distinct areas: the Main Pit and the Southern Expansion Area (Figure 2). Minimal mining activity appears to have occurred in the Main Pit since the last report; however, some faces near the pit bottom appear to have relatively fresh exposures (particularly along the north wall) making direct measurement of discontinuities possible. The sump location appears to look similar overall to the 2012 investigation; however, the pump was not running at the time of our March 2013 site visit. Significant mining activity has taken place in the southern expansion area since our last annual report and between our October 2012 and March 2013 site visits (Photos 1 and 2). Several benches were actively being mined during our March 2013 site visit, including an upper bench near the western margin of the Southern Expansion Area (see stations 13 -04 and 13 -07 in Figure 2). The next lower bench is being mined starting from the eastern side of this level and working to the west. An additional area of recent mining was observed in the northwestern portion of the Southern Expansion Area (see station 13 -06 in Figure 2). This area may represent the start of a new bench level for the next lower bench of the Southern Expansion Area. Based on the current mine plan developed by Martin Marietta (formerly Lafarge West, Inc.) in December, 2003 and the current Colorado Division of Minerals and Geology mine plan, we understand that the mine will eventually be excavated to the topographic configuration shown in Figure 2, with an approximate final mine floor elevation of approximately EL 6,200 ft. The orientation of the planned final mine high walls is the basis for our rock slope stability assessment, as discussed in Section 6.0. April 22, 2013 Page 6 Lachel & Associates, Inc. Project 12361005 00 ©2013 All Rights Reserved