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Coulson Eacavating Company, Inc. -Stroh Gravel Pit Exhibit D -Mining Plan Mining Operations and Timetable Approximately 300,000 tons of gravel will be extracted from the pit each yeaz. Gravel extraction will follow standard gravel mine operations and is expected to follow an annual schedule similar to that shown in Table 3. The monthly gravel tonnages shown are approximate. The sequence in which mining will occur is constrained by the following: (i) The presence of occupied Preble's meadow jumping mouse (PMJM) habitat along the riparian corridor. (ii) The encroachment of the floodway along portions of the northern section of the pit. (See Exhibit D -Mining Plan) Suitable mouse habitat is present along the Big Thompson River on the north boundary of the proposed pit. Therefore, the U.S. Fish and Wildlife Service (USFWS) considers this stretch of the Big Thompson River to be occupied by PMJM. PMJM have been shown to forage in areas away from riparian corridors. The USFWS suggested that a permanent buffer at least 100-ft wide be established between the pit and the existing riparian comdor on its north side. As such, the pit boundary was offset 100 ft south of the permit boundary and the area to be mined excludes this strip of land and is referred to as the permanent PMJM buffer (hatched green in Exhibit D). An adjacent 200-ft wide strip from the pit boundary {called a seasonal PMJM buffer - green line in Exhibit D) has been established and will be during winter months when PMJM are in hibernation. A hydraulic modeling study was performed by WSI in the area of the Stroh pit. The results of the study show the floodway encroaches into parts of the pit in the northern section. The southern boundary tine of the north zone was developed by combining the furthest southern boundaries of the seasonal PMJM buffer and the floodway. It is by coincidence that the PMJM active season and flood seasons are similaz. The flood season as determined by Urban Drainage is April t5's through September IS's, whereas the PMJM active season is April 15a' to September 31a. Mining the north zone will be restricted to October 15a' to April 15a'. Restricting the mining of the north zone to non-flood and non- PMJM active season is designed to protect the pit from being captured by the river during seasonal flooding and prevent the take of PMJM due to mining activity. Prior to April I5's of each mining year, all of the north zone will be backfilled to original ground surface elevations. H:\Stroh\word\DMG\working_Exhibit D.doc