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• Roads <br />Both Stevens Gulch and Roatcap Creek roads cross areas <br />of predicted substantial subsidence. However, subsidence <br />should not result in serious damage to the roads provided <br />surface fracturing and cracking does not accompany the <br />subsidence. Any minor damage which occurred could be readily <br />repaired with a grader and/or dozer. The Terror Creek road <br />lies entirely outside the proposed limits of mining and <br />should not be affected by subsidence. <br />Bridges <br />Both the Stevens Gulch road and the Terror Creek road <br />bridges lie beyond the proposed long-term lease area <br />boundaries and outside any areas of predicted subsidence. <br />6.5 LANDSLIDES <br />There are no criteria available on how subsidence can <br />influence the landslides that have been identified within <br />the future lease area. With proper knowledge and <br />understanding of the landslides' character, certain <br />predictions on this influence can be made. <br />• Large and old landslides identified by Junge (1978) <br />will not, in all probability, be influenced by subsidence. <br />Their origin is related to different climatic conditions. <br />The renewal of their deformations under present climatic <br />conditions is considered improbable under the influence of <br />subsidence. <br />In our opinion, only recent landslides, concentrated on <br />eastern slopes of all North Fork tributaries, may be <br />influenced by mining. As they are concentrated in areas <br />close to the D-seam outcrop, renewal of their deformations <br />would more probably be related to potential failures of <br />outcrop barrier pillars rather than to subsidence. As <br />discussed previously in the report, failures of outcrop <br />barrier pillars could cause new landslides in any mine <br />portion close to the coal outcrop; adequa*_e outcrop barrier <br />pillars should prevent any renewal of these slides or <br />triggering of new slides. <br />Any surface facilities construction on unstable, steep <br />slopes of the tributaries or within the oid landslides could <br />cause new sliding or renewer: doiormatior.s of old landslides <br />when improperly designed. <br />• <br />_ >> _ <br />