2025-06-30_PERMIT FILE - C1981019A ‎(3)‎

• Permit No: C1981019A
• IBM Index Class Name: Permit File
• Doc Date: 6/30/2025
• Doc Name: Volume 1 Rule 4
• Section_Exhibit Name: Rule 4 Performance Standards
• Media Type: D
• Archive: Yes

RULE 4 PERFORMANCE STANDARDS

Rule 4 Performance Standards 4-43 Revision Date: 4/9/25
Revision No.: MR-261
(25% weight), and the Collom Aspen reference area (23% weight) in accordance
with Rule 4.15.7(4)(b).
 Collom Reclamation Areas
o Areas reclaimed to grazing land shall be compared to weighted parameters from
the Mountain Shrub reference area (39% weight), the Sagebrush reference area
(47% weight), and the Grassland reference area (14% weight) in accordance with
Rule 4.15.7(4)(b).

4.15.8 Revegetation Success Criteria

Colowyo will meet the requirements to ensure that the post-mining vegetation will be adequate for
final bond release. As described in Section 4.15.7, Colowyo will utilize the reference areas for
comparisons between reclaimed areas and appropriate native reference areas for the variables of
ground cover and production. For the variables of woody plant density and species diversity,
Colowyo shall compare revegetated areas against defined standards (detailed later in this section).
Data to be used in these comparisons must be from statistically adequate sampling (where
necessary) as indicated in Rule 4.15.11.

Herbaceous Cover
For revegetation targeting (and achieving) the rangeland land use subcomponents of grazingland
and wildlife habitat, herbaceous cover of the revegetated area will be considered adequate for final
bond release if it is not less than 90% of the herbaceous cover as determined from the reference
areas with a 90% statistical confidence utilizing a standard students statistical t-test comparison of
the means, as described in Rule 4.15.8 (3) (a).

Herbaceous Production
For revegetation targeting the rangeland land use subcomponents of grazingland and wildlife
habitat, herbaceous production of the revegetated area will be considered adequate for final bond
release if it is not less than 90% of the herbaceous production, as determined from the reference
areas with a 90% statistical confidence utilizing a standard students statistical t-test comparison of
the means, as described in Rule 4.15.8 (4).

Woody Plant Density
Where shrubs establish to form wildlife habitat, they will be segregated into low and high-density
areas, each with a separate woody plant density success criterion. On high-density areas (areas of
shrub concentration), the standard shall be 375 live woody plants per acre. At least one-half of
these totals shall be sagebrush species. In low-density areas, the standard shall be 200 plants per
acre. Furthermore, Colowyo will establish wildlife habitat areas, comprised of both low and high-
density areas, on approximately 20% of the acres in each bond release evaluation, with at least
50% of those acres representing high-density areas. The grazingland acres will not be subject to
woody plant density standards.

Tall Shrubs and Aspens
For the South Taylor reclamation areas, as part of the revegetation success criteria for those areas,
Colowyo will establish 18.5 acres of aspens and 12.0 acres of tall shrubs. This will be
accomplished through large singular plots or various small plots that add up the acres noted