2012-04-10_REVISION - M1981185 ‎(43)‎

• Permit No: M1981185
• IBM Index Class Name: REVISION
• Doc Date: 4/10/2012
• Doc Name: TECHNICAL REVISION ‎(TR02)‎
• From: WILDCAT MINING CORP.
• To: DRMS
• Type & Sequence: TR2
• Email Name: DMC
• Email Name: SSS
• Media Type: D
• Archive: No

INTRODUCTION
This Work Plan presents Wildcat Mining Corporation's (Wildcat) approach to stabilize and repair the
access road from County Road 124 to the La Plata River for the May Day Idaho Mine Complex. The
May Day Idaho Mine Complex is located in La Plata County approximately 15 miles west of
Durango, Colorado.
Wildcat is proposing to operate the May Day Idaho Mine Complex and is in the process of activating
MSHA mine identification (ID) number 05- 03674. Upon ID activation, MSHA's review and DRMS
approval of this Work Plan, Wildcat will implement the corrective actions described herein.
In May 2010, a site reconnaissance was conducted by J. Erich Rauber, PE to evaluate the stability
of the existing temporary access road from County Road 124 to the La Plata River (the New Access
Road). The New Access Road was constructed around May 2008 to provide a more direct path of
access to the mine property. This road was closed by the Colorado Division of Reclamation, Mining
and Safety (DRMS) due to concerns related to the quality, thickness and degree of compaction of
the road fill and the stability of the existing timber retaining wall on the outboard side of a portion of
the road.
Of particular interest during the site reconnaissance was an approximately 500 foot long section (the
"cut- through" section) approximately 450 feet east of County Road 124. The section of road has
longitudinal grades in excess of 15% and slope embankments to the east and west steeper than 2
horizontal to 1 vertical (2:1). Also, as mentioned above, a timber retaining wall was constructed on
the down slope side of the road and was failing in some sections, and in other sections, the retaining
wall was leaning down slope as much as 20 degrees.
After a site investigation by DRMS, an order was issued (MV- 2009 -033) that prohibits the use of the
New Access Road until DRMS determines that it has been adequately reconstructed to
accommodate the anticipated traffic that will use this road during mining operations. Wildcat
submitted as Exhibit D, Attachment D -1 to its amended Section 112d permit application New Access
Road Construction Work Plan (the Original Work Plan). This Original Work Plan generally
addressed proposed grading for the New Access Road, drainage repairs and the removal and
replacement of the retaining walls on the down slope side of the road. Additional information was
required at the time of approval of the Original Work Plan, including primarily a geotechnical
investigation. Wildcat committed to submitting a Technical Revision (TR) for review and approval by
DRMS once the additional information was available. More specifically, as summarized by Mr.
Hayes in his Memorandum dated September 23, 2011, the following items have been addressed
(responses are in italics):
• Stability of cut slopes in rock and colluviums areas.
Stability of cut slopes has been detailed in Section 3.4 — Stability Analysis of the Rule 6.5
Geotechnical Stability Report.
• Slope configuration for the cut slopes.
Slope configuration for the cut slopes have been detailed in Section 5.2 — Roadway Grading
of the Rule 6.5 Geotechnical Stability Report and are shown on the Construction Drawing
Plan and Profile sheets.
• Carrying load for the reconstructed access road with justification for the proposed load in
accordance with La Plata County Requirements.
The Rule 6.5 Geotechnical Stability Report used a 40 -ton vehicle load for their analysis. The
weight of the vehicle was determined based on the maximum load anticipated to use the
New Access Road. This County's standard weight limit is 8,000 pounds per wheel
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