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<br />impressive of these features examined measured approximately 30 feet across and twenty feet in <br />depth, extending for a length of approximately 100 feet. Several of these troughs have been the <br />locus of "natural" stock watering ponds. Most of these ponds have been dewatered by the recent <br />landslide activity. Judging from the size of Aspen growth and the degree of smoothing by <br />weathering of the graben side slopes, Dr. Pendleton estimates that these larger features are in <br />excess of a century in age. DMG also examined several smaller troughs with widths of five to ten <br />feet and depths in the five foot range. These smaller grabens were less weathered, retaining <br />smoothed but steep-sided trapezoidal shapes, and were less vegetated with small aspen saplings <br />and scrub oak, suggesting ages of several decades. While these estimates of age are based on <br />Dr. Pendleton's experience and may be grossly flawed, the comparative age of these features and <br />the active landsliding demonstrate that recurrent episodes of landsliding have affected this area. <br />Subsidence Cracking on Jumbo Mountain <br />At several locations during our tour of the site, DMG examined cracking which appeared <br />indicative of subsidence troughing without landslide translational movement. Sites designated on <br />the MCC maps as #2, #3 and #8 fall into this category. These cracks are generally smaller in <br />width (2 to 6 inches), and demonstrate no translational or lateral offset between the opposite faces <br />of the cracks. Their orientation tends to sub-parallel the axis of the panel or the longwall face. <br />Relationship of Subsidence and Landslide Occurrence <br />Because of the proliferation of landslides throughout the North Fork valley, the DMG has <br />repeatedly expressed a concern regarding the possible reactivation of ancient, historic and modern <br />landslides during mine permit review. This same concern is commonly expressed by land owners <br />and the public. The DMG has included permit conditions requiring every mine with mapped <br />landslide deposits above projected subsidence to monitor the stability of known landslide deposits <br />to determine whether any reactivation were to occur. The Bear Mines and the West Elk Mine <br />were both required to monitor known landslides adjacent to Somerset. While these landslides <br />subsided several feet no reactivation has occurred. The Orchard Valley mine (Bowie #1) was <br />required to monitor known landslides in Stevens Gulch and adjacent to its Portal facilities. None <br />of these landslides evidenced reactivation. These same requirements have also been placed on <br />underground coal and hardrock mines in other areas of the State of Colorado. To date, while they <br />have been subsided, none of the monitored landslides have evidenced any reactivation. At the <br />same time, every one of these mines has continued to evidence landslide occurrence, both in and <br />outside subsided areas within the permit and adjacent areas. Based upon this experience, <br />Dr. Pendleton concludes that subsidence does not appear to be a significant determinant in the <br />reactivation or initiation of landslide activity. <br />Mautz Guest Ranch Cabin <br />Subsequent to the approval of the MCC permit revision to conduct mining of the 'B' seam beneath <br />Jumbo Mountain, Mr. Mautz erected a guest ranch cabin above the gate roads between Panel 8 <br />and Panel 9. This location had been predicted to experience potentially damaging subsidence <br />within the approved permit documents. That cabin subsequently experienced subsidence and <br />3 <br />