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PROPERTY, PLANT AND EQUIPMENT (Tables)
12 Months Ended
Dec. 31, 2021
PROPERTY, PLANT AND EQUIPMENT  
Schedule of property, plant and equipment

    

December 31,

 

2021

    

2020

(in thousands)

Mining equipment and processing facilities

$

1,896,470

$

1,896,324

Land and coal mineral rights

 

458,440

 

454,310

Oil & gas mineral interests

647,864

616,904

Buildings, office equipment, improvements and other miscellaneous equipment

 

282,902

 

279,938

Construction, mine development and other projects in progress

 

44,217

 

25,799

Mine development costs

 

278,454

 

280,815

Property, plant and equipment, at cost

 

3,608,347

 

3,554,090

Less accumulated depreciation, depletion and amortization

 

(1,909,669)

 

(1,753,845)

Total property, plant and equipment, net

$

1,698,678

$

1,800,245