PROPERTY, PLANT, AND EQUIPMENT, NET
 12 Months Ended
Dec. 31, 2013
Property, Plant and Equipment [Abstract]  
PROPERTY, PLANT, AND EQUIPMENT, NET
PROPERTY, PLANT, AND EQUIPMENT, NET
Details on property, plant, and equipment, net were as follows:
 
Useful lives (In years)
 
December 31,
 
 
2013
 
2012
 
(Dollars in thousands)
Gas gathering systems
30
 
$
634,177

 
$
427,449

Compressor stations and compression equipment
30
 
351,560

 
237,618

Construction in progress
n/a
 
51,023

 
45,919

Other
4-15
 
7,451

 
4,524

Total
 
 
1,044,211

 
715,510

Accumulated depreciation
 
 
(63,870
)
 
(33,517
)
Property, plant, and equipment, net
 
 
$
980,341

 
$
681,993

The increase in property, plant, and equipment primarily reflects the recognition of gas gathering system fixed assets acquired in connection with the Bison Drop Down and Mountaineer Acquisition. See Note 13 for additional information.
Construction in progress is depreciated consistent with its applicable asset class once it is placed in service. Depreciation expense related to property, plant, and equipment and capitalized interest were as follows:
 
Year ended December 31,
 
2013
 
2012
 
2011
 
(In thousands)
Depreciation expense
$
30,353

 
$
21,337

 
$
8,595

Capitalized interest
4,209

 
2,784

 
3,362