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Memo to Berry/Boulay Jumbo Mountain Landeliding page 3 accommodated in general bulging of the landslide mass, which is normally evidenced by cracking parallel to the fall line. Many such cracks do exist on the active landslide mass. Commonly, the specific translocation of landslide material can only be determined by the comparison of precision pre-failure versus post-failure surveys of the landslide mass. In my opinion, the cracking and disruption which we examined in the SWl/4 of Section 24 on Jumbo Mountain is indicative of a 30 to 50 acre landslide mass. This landslide exhibits characteristics common to modern landslides throughout the North Fork valley. As such I would expect this landslide to undergo several years of active creep, after which it may become more stable. The cracks and troughs affecting roads and trails will require grading to render them passable. Cracks in the off-road areas will close by in-filling and features will become more subdued with erosion. I recommend road repair be more extensive than just filling the crack. If a four or five foot pad of ripped and recompacted material is placed across the major features it will increase the capability of accommodating the continued creep movements which will normally occur for the next several years. Some larger cracks and troughs will undoubtedly required repeated treatment to maintain trafficability. These repairs should restore safe access to the affected area, which may be important for emergency situations on the Mautz's Chipeta Guest Ranch. Continued monitoring should be periodically conducted to determine if additional repairs are required. Signage should be erected to inform users of possible hazards. Recurrence of Jumbo Mountain Landslide Activity My examination of the landslide discerned evidence of recurrent modern (since white man's occupation) activity. In several areas, predominantly in the middle to higher portion of the landslide mass, closed extensional troughs are present. These undrained grabens are caused by downslope movement of landslides pulling away from the upslope headscarps. The most impressive of these features examined measured approximately 30 feet across and twenty feet in depth, extending for a length of approximately 100 feet. Several of these troughs have been the locus of "natural" stock watering ponds. Most of these ponds have been dewatered by the recent landslide activity. Judging from the size of Aspen growth and the degree of smoothing by weathering of the graben side slopes, I estimate that these larger features are in excess of a century in age. I also examined several smaller troughs with widths of five to ten feet and depths in the five foot range. These smaller grabens were less weathered, retaining smoothed but steep-sided trapezoidal shapes, and were less vegetated with small aspen