2025-05-02_REVISION - C1981010 ‎(2)‎

• Permit No: C1981010
• IBM Index Class Name: Revision
• Doc Date: 5/2/2025
• Doc Name: Proposed Decision and Findings of Compliance
• From: DRMS
• To: Trapper Mining, Inc.
• Type & Sequence: PR12
• Email Name: RAR
• Email Name: JLE
• Media Type: D
• Archive: No

Pits to the approximate original contour in accordance with Rule 2.06.5. Based on a stability
analysis provided by TMI with (PR9),they demonstrated that based on unique combinations
of steepness of the pit floor, spoil thickness, spoil saturation, and the presence of a weak
shale/clay layer in the floor of the pit, steep slopes for the final cut of the L Pit and Ash Pit
should be identified as any slope over 16 degrees. For PR12, TMI proposed a modification
of this variance and the post-mining contours in L pit, comprising a shift to the east. The
proposed shift was found to be applicable to the original proposal when hydrology and
sedimentology were reevaluated by DRMS. A stability analysis was again performed by
DRMS and found conservative. Therefore,these areas qualify for a variance from the
requirement to backfill and grade to the approximate original contour under the steep slope
mining provision for the PR12 permitting action. The findings required for a variance in
accordance with Rule 2.06.5 and Rule 4.27.4 are discussed below in the Operations on Steep
Slopes, Section XX of this document.
XI. Revegetation
The Division previously approved Trapper's revegetation plan as set forth in permit Section 3.6,Vol.
III of the application.
1. The applicant uses introduced species in the reclamation seed mix and submitted information
illustrating the desirability and necessity of introduced species in achieving the approved
post-mining land use illustrating that these species are not poisonous or noxious (4.15.2). In
conjunction with Trapper's years of reclamation experience, Trapper has reduced the number
of introduced species in the seed mixes utilized at the site. DRMS found the seed mix
adjustments acceptable.
2. Methods to measure species diversity,woody plant density,herbaceous cover and production
are discussed in permit section 4.4.1,Volume IV. Seed mixes and revegetation practices are
designed to meet diversity standards set forth in the permit. The applicant will reestablish
shrubs on Range Sites A and B by including various native shrubs in the seed mixes and by
transplanting mature woody shrub clumps. There is no shrub density standard for Range Site
C. (4.15.7(1)).
XII. Post-mining Land Use
Post-mining land use is discussed under Section 4.2, Vol. IV of the permit application.
Cropland, rangeland and wildlife habitat are currently approved post-mining land uses.
These land uses meet the criteria of Rule 4.16.3.
XIII. Protection of Fish, Wildlife and Related Environmental Values
Section 4. 6 of Vol. IV of the permit application discusses the protection of fish,wildlife and
related environmental values.
Wildlife habitat is a planned post-mining land use. The applicant selected appropriate
plant species and distributions to benefit fish and wildlife (4.18(4)(i)).
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