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Revised 11/85 form. Instead of forming troughs, the slope will exhibit a slight diminution or increase in slope through the transition zone from subsided area to unsubsided area. The areas within the subsidence limit will be slightly lower than the original terrain. The manner of sliding in which this subsidence takes place does not result in repeated high magnitude vibrations. The vibrations will tend to come to the surface as single events of minor magnitude. Tt is anticipated that subsidence at the Bear No. 3 Mine will have a very minor effect on the stability of the ancient landslide materials found in the area. The landslide area was also of concern during earlier permitting of the Bear No. 3 Mine. Two (2) subsidence monument stations have been placed on the landslide area as shown on the Geology/Hydrology Map (Map 6). The monitoring of these stations will provide information pertaining to subsidence and stability of the landslide material. If landslide material is found to be moving, the current mining activity can be examined to see if it could be the cause • of landslide movement in the area. In the event that mining activity is determined to be the cause of minor landslide movement, the mining plan will be revised to minimize subsidence in the landslide areas, thereby assuring that mining activity will have no effect on the landslide material. In addition, if significant movement is recorded, Bear Coal Company will work with the Division to determine if additional subsidence monitoring stations are required or necessary. Subsidence Effect on Wildlife Habitat and Rangeland. The mine plan proposed at the Bear No. 3 Mine, allows for maximized pillar extraction in the panels and extraction of barrier pillars upon retreat from the mining area. The high recovery rates planned for the C coal seam will result in pillar stumps crushing out after mining. The crushing of the pillar stumps will allow area type subsidence. to take effect in the post-mining area. The nearly complete extraction of the C coal seam will eliminate sink hole type of subsidence commonly found in some room • and pillar mining operations where pillar extraction is not conducted. Although the subsidence reaching the surface could be as much as six feet (6'), it will be continuous over nearly the entire area and, therefore, the affect on wildlife habitat and rangeland will be minimal. _27_