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• the section of road lowered by the landslide movement to the pre- <br />slide level with fill material. Placing this fill material on the <br />top of the slide will add a substantial load to the marginally <br />stable slide area. For this reason it would be desirable to <br />evaluate the performance of both the upper and lower drains to <br />insure that sufficient drainage of the failure surface has occurred <br />before a decision is made on when to place the fill material on the <br />slide area. <br />It is also recommended that the proposed drainage structures <br />be left intact for the post-reclamation configuration of this site <br />in order to maintain the added stability benefit created by the <br />drainage structures. Any of the structures effected during the <br />reclamation process should be relocated to facilitate the post- <br />mining land configuration. <br />STABILITY <br />• The entire slope above the Bear Mine No. 3 site has had <br />engineering geologic mapping done by Mr. Walter R. Junge of the <br />Colorado Geological Survey. The results of this mapping classified <br />this area as "an area consisting of various types of slope failures <br />and mass-wasting features such as landslides, mudflows, rockfalls, <br />and soil creep" (ls,). A large amount of the landslides which <br />occurred in the North Fork Valley this spring possess the same <br />geologic classification. The detailed geotechnical study, <br />performed by RMG, concluded that the site has, with one exception, <br />"a existing condition of marginal stability". This conclusion <br />coincides well with the stability conditions observed by Mr. Junge. <br />It is not economically feasible for the operator to stabilize <br />the entire slope above the mine site. However, the measures taken <br />and proposed to stabilize the recent failure are a cost effective, <br />sound stabilization practice, which cause a minimum of additional <br />environmental disturbance, compared to alternative measures <br />considered at the site. With the implementation of the measures <br />• proposed in this report and the allocation of sufficient time to <br />21-11 <br />