December 31,

2024

2023

(in thousands)

Mining equipment and processing facilities

$

2,131,697

$

1,989,541

Land and coal mineral rights

508,892

504,736

Oil & gas mineral interests

878,083

853,350

Buildings, office equipment, improvements and other miscellaneous equipment

315,092

310,876

Construction, mine development and other projects in progress

213,579

184,895

Mine development costs

388,192

329,146

Property, plant and equipment, at cost

4,435,535

4,172,544

Less accumulated depreciation, depletion and amortization

(2,269,265)

(2,149,881)

Total property, plant and equipment, net

$

2,166,270

$

2,022,663