GENERAL31911

• Permit No: C1981029
• IBM Index Class Name: General Documents
• Doc Date: 5/6/1986
• From: INTRASEARCH INC
• To: SUN COAL CO
• Permit Index Doc Type: GENERAL CORRESPONDENCE
• Media Type: D
• Archive: No

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IntraSearch Int. Swte 200 Cable IN TRADEN
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999
May 6, 1986
Mr. Brian Archer
Sun Coal Company
5449 Ward Road, Suite 110
Arvada, Colorado 80002
Dear Mr. Archer:
This letter is in response to your request for a brief summary
regarding the results of our recent slope stability map interpretation
of the Coal View Gulch area, Routt County, Colorado.
IntraSearch was requested on April 11, 1986 to conduct a stereoscopic
inspection of both recent and historic aerial photography for the
purpose of ascertaining the post-construction effects to the local
terrain of Sun Coal Company's mine haul road. The gravel road,
constructed in 1977, connected the Meadows No. 1 surface coal mine
located in the east central part of Sec. 23, T. 6 N., R. 87 W. with a
loading facility located south of the Yampa River in the north central
part of Sec. 14, T. 6 N., R. 87 W.
Slopes south of the river have been affected by landsliding in the
past. The major landslides in the study area are ancient and in most
cases have reached a high degree of stability.
The geology of the road site involves steep, west dipping strata of
the Iles formation of the Mesaverde group, inclined approximately 12
degrees on the west flank of the Tow Creek Anticline. Exposed within
the study area are mostly sandstones, mudstones, shales and coal beds
in an alternating sequence of resistant and non-resistant units.
From our investigation the road appears to be well positioned on the
downdip slope of a resistant, competent sandstone, not commonly
subject to slope failure, provided proper surface drainage exists.
Present drainage does not appear to be obstructed by the presence of
the road. Adequate drains or culverts appear to be properly
positioned and operational.
A locality for potential slope failure in proximity to the road is an
old pre-1938 surface mining disturbance located in the center of Sec.
14, T. 6 N., R. 87 W. Drainage of surface waters appears to be have
been interrupted, causing water to pond and enter the soil and