2024-12-16_REVISION - M1977410 ‎(2)‎

• Permit No: M1977410
• IBM Index Class Name: Revision
• Doc Date: 12/16/2024
• Doc Name Note: Table of Contents, Introduction Exhibit A Thru Exhibit U Appendix A Thru Appendix G
• Doc Name: Request For Conversion
• From: Grand Island Resources LLC
• To: DRMS
• Type & Sequence: CN1
• Email Name: JPL
• Email Name: JLE
• Email Name: EL1
• Email Name: LJW
• Email Name: THM
• Media Type: D
• Archive: No

Cross Gold Mine
December 2024 E-4

There are currently two ventilation shafts, one shaft, one adit, and two portals that will require closure
as listed in Table E-2. All shafts, adits, portals, and ventilation shafts will be closed according to the
Colorado Inactive Mine Program standards and specifications (DRMS 2009).
Table E-2. Shafts and Portals
Name Size (feet)
Cross Mine Adit 8x8
Idaho Tunnel Portal 12x12
Caribou Level 300 Portal 8x8
Potosi Shaft 6x6
Cross Ventilation Shaft and Escapeway 10x5
Cross Ventilation Shaft 5x5
Cross Mine Adit
The Cross Mine Adit will be closed using the concrete block wall closure shown in Figure 1 of Appendix
E-1. Concrete blocks will be 8x8x16. The Cross Mine Adit closure is estimated to be 8 x 8 feet in
vertical and horizontal dimension (Sections A and B in Figure 1 of Appendix E-1). The snowshed will be
removed prior to closure and the materials recycled or disposed of according to the reclamation plan
(Section 1.1). The adit closure will be fenced with a 5x5 foot chain link fence and will be posted for
hazard and trespass. Approximately 25 square feet will be revegetated.
Idaho Tunnel Portal
The Idaho Tunnel Portal will be closed using the concrete block wall closure shown in Figure 1 of
Appendix E-1. Concrete blocks will be 8x8x16. The Idaho Tunnel portal closure is estimated to be 12 x
12 feet in vertical and horizontal dimension (Sections A and B in Figure 1 of Appendix E-1). The
snowshed will be removed prior to closure and the materials recycled or disposed of according to the
reclamation plan (Section 1.1). A 2 x 2 x 0.25-foot grated access door will be installed that will be used
in the block wall to provide for water inspection. The portal closure will be fenced with a 50-foot chain
link fence and posted for hazard and trespass. Approximately 25 square feet will be revegetated. The
Idaho Tunnel slope has a horizontal area of approximately 0.147 acres and a slope surface of
approximately 0.178 acres. Based on the results of the slope analysis described in the approved
Technical Revision (TR) No. 9, which indicates that the slope is stable, the slope surface will be graded
to approximate original contour with a slope no greater than 2:1 using materials left from historic and
current operations. If conditions change (bulkhead addition or other conditions), additional slope
evaluation may be required in the future and would be provided to DRMS as a TR. GIR anticipates
using a DR7 (or equivalent bulldozer) to regrade the slope. The area (approximately 0.178 acres) will
be covered with 1 foot of topsoil in accordance with Section 1.10. Topsoil will be graded using a DR7
(or equivalent bulldozer). Topsoil will come from disturbance associated with diversion structure
installation and the construction of the Caribou Access Road. Revegetation will be in accordance with
Section 1.11. Seed will be used to provide a vegetative cover that is consistent with the DRMS Inactive