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2019 Plan of Operations Modification American Gypsum Company, LLC 6.6 Roads and Utilities 6.6.1 Roads The proposed Upper Pit expansion area would be accessed using approximately 1.32 miles of existing access roads (starting at the Mine entrance location shown on Drawing 03). Roads were cleared of vegetation before construction. Juniper and pinion trees removed during vegetation clearing were stockpiled outside the construction area for use in future reclamation. Roads were constructed using cut-to-fill methods,with a 50-foot wide road to accommodate two lanes of traffic with safety berms and side drainage ditches. Culverts were installed where the road crossed drainages. Haul roads will be reclaimed as described in existing permits (CO DRMS, 2001; BLM, 2002). The 1.32 miles of existing roads used to access the proposed Upper Pit expansion area includes approximately 0.06 miles of the approved Upper Pit 6900 Access Road (BLM, 2019; CO DRMS, 2019a). As the Upper Pit progresses past a pit floor elevation of 6900 feet amsl, a second road (approximately 0.08 miles long) would be constructed utilizing the partially reclaimed northern section of the Upper Pit and the southern section of the Upper Pit 6900 Access Road would be abandoned. As the Upper Pit depth increases, interior roads would be incorporated into the Upper Pit to continue accessing the lower portions of the Upper Pit. Drawing 16 shows the conceptual road configuration. Interior roads would be developed as the pit is developed and are not shown on the ultimate pit configuration shown on Drawings 06 and 07; the conceptual internal Upper Pit road configuration may be modified during operations but would be constructed within permitted disturbance areas. The East Pit would also be accessed via approximately 1.32 miles of existing access roads, 0.8 miles of the new Upper Pit 6900 Access Road, extending east across the Upper Pit and existing intraburden storage, and approximately 0.2 miles of road within a new disturbance area before terminating at the East Pit. Another 0.28 miles of the new East Pit Access Road would be constructed within the East Pit footprint and would be removed as the East Pit is mined, leaving only 0.02 miles of the road within areas previously undisturbed (excluding the East Pit disturbance area). All new roads would be 50 feet wide (including safety berms), with 1.5H:1V cut and fill slopes to tie into existing topography(using cut-to-fill methods where possible and utilizing inert intraburden for the remaining fill). Roads would have a maximum 8% longitudinal grade and would be graded with a high point in the center (crown) of the road (at 1.0%) so stormwater runs off the road. Culverts would be installed where the road fill crosses drainages (stormwater controls are discussed in Section 8.0 and culvert details are shown on Drawing 10). Finished road fill slopes (that are not intended to see traffic) would be track-walked and revegetated immediately after construction or as soon as weather allows using an approved seed mixture. The Upper Pit/East Pit Access Road construction would require approximately 536,000 cubic yards of cut and 1.415 million cubic yards of fill. An additional 163,000 cubic yards of material would be removed from the Upper Pit 6900 Access Road (BLM, 2019; CO DRMS, 2019a) to accommodate the increased Upper Pit footprint and used as fill material for road construction or backfill for progressive reclamation activities. The remaining 716,000 cubic yards of fill required Am Gypsum Poo Mod ISSD 20190909 September 2019 [24]