(1) All machinery and equipment used in the mining process is classified as class eight property, 15-6-138 , MCA.

(a) Mining machinery and equipment included in class eight property shall be that equipment engaged in the extraction, excavation, burrowing or otherwise freeing raw material from the earth.

(b) Mining machinery and equipment shall be valued by trending the original installed cost to a current replacement cost, and depreciating on an age/life basis to compensate for ordinary physical wear and tear and obsolescence.

(2) Mobile equipment used in the mining operation for extraction shall be valued by using the procedures established for heavy equipment in ARM 42.21.131.

(3) Mobile mining equipment is equipment that moves under its own power and/or on its own wheels and chassis, including any attachments used with or attached to such equipment. Mobile equipment does not include equipment that requires a foundation for the performance of the function for which it was designed and built.

(4) The trended depreciation schedule referred to in (1) (b) is found in ARM 42.22.1311, Table 21, Mine Mill and ARM 42.22.1312.