2023-06-29_PERMIT FILE - C1981019A ‎(2)‎

• Permit No: C1981019A
• IBM Index Class Name: Permit File
• Doc Date: 6/29/2023
• Doc Name: Volume 1 Rule 4
• Section_Exhibit Name: 4.01 Through 4.30
• Media Type: D
• Archive: Yes

RULE 3 PERFORMANCE BOND REQUIREMENTS

Rule 4 Performance Standards 4-40 Revision Date: 6/13/23
Revision No.: MR-247
for livestock and wildlife, but are no longer a component of the desired post-mining vegetation
communities.

For post-2008 revegetation, the seed mixes (please see Tables 2.05.4-7 through 2.05.4-9) are
comprised entirely of native species, except with the inclusion of modest quantities of small burnett
or nitrogen fixing legumes such as cicer milkvetch or alfalfa as supplemental forage for wildlife.

4.15.3 Seeding and Planting

Please refer to the reclamation plan found in Section 2.05.4

4.15.4 Mulching and Other Soil Stabilizing Practices

As addressed in Section 2.05.4, Colowyo currently does not mulch, chisel plow, or terrace, because
experience demonstrates sufficient surface roughness survives the topsoil laydown process to
maintain favorable seed-bed conditions. If conditions warrant additional topsoil manipulation,
Colowyo will utilize an appropriate practice specific to the circumstance. Best management
practices, such as minimizing topsoil handling and manipulation, ripping along the contour,
disking, or cross ripping will be implemented and are further discussed in Section 2.05.4.

4.15.5 Grazing

All the lands reclaimed by Colowyo will not be grazed by livestock for a period of at least three
years after seeding or planting and will be managed to promote the postmining land use.

Grazing by livestock will not commence until Colowyo has demonstrated to the satisfaction of the
Division that the vegetation on the reclaimed surface is adequately established and can be expected
to withstand grazing pressures. Any grazing studies undertaken by Colowyo will not preclude or
interfere with postmining vegetation sampling as required in section 4.15.8.

4.15.6 Field Trials

As a result of previous consultations with CPW and DRMS, Colowyo implemented three field
trials. The field trials were meant to provide information to the appropriate expectations for
success/failure of establishing these habitat types at Colowyo in the context of a ten-year bond
clock, to provide some baseline information that can be used to modify practices, and the plant
materials used to meet the current expectations.

The study was comprised of three test scenarios designed to explore different species and habitat
requisites necessary for tall shrub survival. The first treatment was to establish an overstory of
quaking aspen (Populus tremuloides) trees that are planted into deep topsoil (48 inches). The
second treatment was serviceberry (Amelanchier alnifolia) and chokecherry (Prunus virginiana)
shrubs planted into deep topsoil (48 inches). The third and final treatment was serviceberry and
mountain mahogany (Cercocarpus montanus) shrubs planted into shallow topsoil (4 inches). The
aspen trees and/or tall shrubs were planted in ten-220-foot long rows per treatment, for a total of
550 plants per treatment. The initial planting consisted of 550 quaking aspen tubelings in the first