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003330 In summary the most important accomplishments to date at Meadow Mountain are installation of a landslide movement-monitoring system in a compoun. landslide system whose various components exhibit differing styles of movement. The "intermediate" landslide is the most threatening because approximate but reasonable estimate(s) of volumes of material that could move and its current movement indicate that it alone could dam the Eagle River, at least temporarily, and permanently close the present alignment of U,S. Highway 24, Such an event could be precursor to even larger scale movements in the main Meadow Mountain feature as toe support in it would be considerably reduced. Prediction of this is still impossible considering the relatively small amount of data that a limited drilling program and short-term monitoring of EDM and inclinometer stations has made available, ( , Dowds No.1 Landslide The Dowds No, 1 landslide, located south of the Eagle River at Dowds Junction, has had a recognized but poorly documented history of movement since Interstate Highway 70 was built that has dislocated and damaged the nearby highway bridge and its western approach. Prior to our field study of this feature it was not known whether large scale catastrophic failure of the landslide is possible, whether movement of it is seasonal. or whether the overall composition of the landslide 'varies areally or with depth, Because of the urgency to determine if catastrophic failure of the Dowds No, 1 landslide was possible in the spring or summer of 1985 the first task assigned to, the CDOH drilling crew was to drill two core holes at its base for the purpose of installing inclinometers, These drill holes were made between the on and off ramps to Interstate 'Highway 70 and the bridge abutment of the highway bridge and 'were drilled to 180,5 ft (hole 1) and 160,5 ft (hole 2) below ground level respectively (See location map,). They were drilled through ancient river gravels, which represent a former course of the ancestral Eagle River, into Minturn Formation bedrock, In hole 1 several, important subsurface features were noted in the core, Several shear zones were encountered with the first occurring at about 45 ft, another at 75 ft where surprisingly a piece of non-carbonized wood was cored (This was subsequently radiocarbon dated as 8440 + 100 years before present,) and the one that we interpreted as the basal landslide shear zone at 165 ft below the ground surface, The ancient river gravels were encountered nearly continuousJy in the cor;e,demonstrating that,the_l an,dslide'dor a,t,l east the toe or lower part of it involved and probably forced the'river course to the north, Whether this movement dammed the river in the past is not known, but it appears as if this certainly might have occurred, This appears to justify concern that such an event could happen today, The second hole was virtually identical to the first except the basal shear was interpreted to be at 142 ft, - 8 - ( ,.