The major categories of plant and equipment are depreciated on a straight-line basis using the estimated lives indicated below:
Vehicles
5 years - 7 years
Mining equipment
3 years - LOM
Mobile equipment components
2 years - 7 years
Buildings
LOM
Mine plant equipment
LOM
Underground infrastructure
LOM
ROU assets - plant and equipment (1)
10 years - LOM
(1)For ROU assets, the depreciation period indicated above represents the period from lease commencement date to the earlier of the end of the useful life of the underlying asset or the end of the lease term.
The components of Mineral properties, plant and equipment, net were as follows (in thousands):
December 31,
20252024
Plant and equipment (1)
$2,097,802 $1,883,193 
Construction in process
 232,646  135,594 
Mineral properties subject to depletion

2,331,466 2,114,765 
Mineral properties not yet subject to depletion
 896,214  884,029 
Exploration and evaluation assets

247,164 254,146 
Total mineral properties, plant, and equipment 5,805,292  5,271,727 
Accumulated depreciation, plant and equipment

(931,887)(804,411)
Accumulated depreciation, mineral properties(740,151)(684,449)
Mineral properties, plant, and equipment, net$4,133,254 $3,782,867 
(1)As of December 31, 2025 and 2024, plant and equipment includes finance lease right-of-use assets with a carrying amount of $73.3 million and $78.9, respectively.

About PP&E Disclosures

The PP&E disclosure details a company's physical asset base — land, buildings, machinery, and equipment — along with the depreciation methods and useful life assumptions that determine how these costs flow through the income statement. Capitalization policy thresholds reveal management's judgment on the boundary between expense and asset, directly affecting both reported earnings and asset values.

Key signals: changes in estimated useful lives or depreciation methods can materially shift reported earnings without any operational change. Compare capital expenditures against depreciation expense — when capex consistently trails depreciation, the asset base may be aging and underinvested. Watch for large asset impairments or write-downs that signal overvalued carrying amounts. Asset retirement obligations reveal future environmental or decommissioning costs that are often underappreciated. Compare PP&E intensity (PP&E-to-revenue) against industry peers to assess capital efficiency and competitive positioning.