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2004 Geologic Hazard Field Observations <br />South of Divide Mining Area <br />• 9.5 Roads <br />With the exception of the presence of minor subsidence cracks on an access road to Jumbo <br />Mountain, no subsidence features (cracks or bulges) were observed during the annual subsidence <br />observations. Large, extensive cracks were observed on Jumbo Mountain in landslide areas. <br />However, they were considered to be exclusively caused by the natural landslide process. <br />Based on past observations in the Apache Rocks and Box Canyon mining areas, no significant <br />effects due to mine subsidence are expected on most of the access roads and drill road in the <br />South of Divide area. Also, no effects from landslide movements or rockfalls aze expected, <br />because the highest rockfall potential is mapped in the high category. Rockfalls were observed to <br />occur only in the very high rockfall category areas in the Box Canyon mining azea. <br />Although no cracks are expected in the soft, pliable alluvium, some cracks aze expected to occur <br />on the more compacted Dry Fork access road, particulazly in the area neaz the confluence of Deer <br />Creek and Dry Fork. As discussed previously, the range of maximum vertical displacement, tilt, <br />• and horizontal strain is projected to be 8.4 to 11.2 feet, 1.3 to 6.4 percent, and 0.7 to 4.2 percent <br />(respectively) in the North Fork stream valley and road above the western limits of longwall <br />panels EZ and E3. <br /> <br />9.6 Buildings <br />Subsidence effects on buildings have not been observed in the Apache Rocks and Box Canyon <br />mining areas. Baseline information on buildings, such as foundations, walls, chimneys, and <br />roofs, has akeady been obtained prior to any mhiing on the Dry Fork Cow Camp in July 2004 <br />Pre-mining information is planned on all buildings in the South of Divide mining area prior to <br />mining. <br />831-032.621 Wright Water Engineers, Inc. Page 38 <br />November 2004 <br />