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-50- The applicant proposes to implement a subsidence control plan to mitigate Impact upon the inventoried structures and renewable resource lands within the permit area. Within the areas delineated on Maps A and B within Exhibit 4-H, the applicant proposes to limit extraction to development entries with limited cross-cuts. The proposed development entry configurations limit coal extraction to a maximum of approximately 34% of the in-place coal within the boundaries of the developed entry sets. This limited extraction plan will be implemented beneath the valleys of Middle and North Thompson Creeks, as well as their associated alluvial deposits. County Road 108 and all potentially affected mine surface facilities will also be protected through utilization of the limited extraction control plan. The areas to be extracted utilizing the limited extraction plan are delineated to reflect an angle of draw of 35o in the up-dip direction and 45o in the down-dip direction from the proposed underground workings. The applicant proposes a subsidence monitoring program to verify the projections of anticipated subsidence presented within the permit application. Visual monitoring will be conducted periodically in order to observe surface cracking occurrence and configuration changes through time. Hydrologic monitoring will be conducted to observe surface water infiltration and aquifer performance changes through time. Leveling points will be installed in connection with the surface facilities of the 1ne. leveling point surveying monuments will also be installed above any limited extraction entries within the areas designated for control plan implementation on Maps A and B of Exhibit 4-H. The applicant will also utilize the monitoring results of an on-going U.S. Department of Energy funded subsidence monitoring program now being conducted above the workings of the No. 1 North Thomppon Creek Mine. In order for the Division to deem the subsidence control plan to be in compliance with the regulatory requirements, the Division deems it appropriate to impose the following subsidence monitoring stipulation: Stipulation No. 9 THE DIVISION DIRECTS SNOWMASS COAL COMPANY TO INSTALL SUBSIDENCE MONUMENTATION, AS DESCRIBED WITHIN EXHIBIT 4-H OF THE PERMIT APPLICATION, ABOVE ANY UNDERGROUND WORKINGS INSTALLED WITHIN THE LIMITED EXTRACTION AREAS INDICATED ON MAPS A AND B DF EXHIBIT 4-H. SURFACE SUBSIDENCE MONUMENTS SHALL BE INSTALLED AND SURVEYED AT LEAST ONE MONTH PRIOR TO UNDERMINING. With the imposition of the above stipulation, the Division finds the subsidence evaluation, subsidence control plan and subsidence monitoring program to be in conformance with the requirements of this Section. XXII. Special Categories of Mining -