PROPERTY, PLANT AND EQUIPMENT:



	December 31,
	2014		2013
Coal & other plant and equipment	3,726,514		3,681,051
Intangible drilling cost	2,798,394		1,937,336
Proven properties	1,768,007		1,670,404
Unproven properties	1,540,835		1,463,406
Coal properties and surface lands	1,358,306		1,404,056
Gathering equipment	1,088,238		1,058,008
Wells and related equipment	716,748		688,548
Airshafts	468,924		397,466
Leased coal lands	263,946		393,372
Coal advance mining royalties	386,245		381,348
Mine development	414,501		354,607
Other gas assets	123,539		126,239
Gas advance royalties	20,580		22,668
Total Property, Plant and Equipment	14,674,777		13,578,509
Less Accumulated Depreciation, Depletion and Amortization	4,512,305		4,136,247
Total Net Property, Plant and Equipment	$	10,162,472	$	9,442,262

The following assets are amortized using the units-of-production method. Amounts reflect properties where mining or drilling operations have not yet commenced and therefore, are not being amortized for the years ended December 31, 2014 and 2013, respectively.



	December 31,
	2014		2013
Unproven gas properties	$	1,540,835	$	1,463,406
Coal properties	477,444		273,242
Mine development	11,984		238,356
Leased coal lands	50,044		99,506
Coal advance mining royalties	52,009		48,043
Airshafts	52,194		38,794
Gas advance royalties	20,580		22,668
Total	$	2,205,090	$	2,184,015

As of December 31, 2014 and 2013, plant and equipment includes gross assets under capital lease of $87,055 and $96,015, respectively. For the years ended December 31, 2014 and 2013, the E&P division maintains a capital lease for the Jewell Ridge Pipeline of $66,919, which is included in Gas gathering equipment. For the years ended December 31, 2014 and 2013, the E&P division also maintains a capital lease for vehicles of $10,207 and $10,652, respectively, which are included in Other gas assets. For the years ended December 31, 2014 and 2013, the All Other segment maintains capital leases for vehicles and computer equipment of $9,929 and $18,444, respectively, which are included in Coal and other plant and equipment. Accumulated amortization for capital leases was $49,735 and $50,371 at December 31, 2014 and 2013, respectively. Amortization expense for capital leases is included in Depreciation, Depletion and Amortization in the Consolidated Statements of Income. See Note 15–Leases for further discussion of capital leases.

Industry Participation Agreements

CONSOL Energy has two significant industry participation agreements (referred to as "joint ventures" or "JVs") that provided drilling and completion carries for our retained interests.

CNX Gas Company is party to a joint development agreement with Hess Ohio Developments, LLC (Hess) with respect to approximately 153 thousand net Utica Shale acres in Ohio in which each party has a 50% undivided interest. Under the agreement, as amended, Hess is obligated to pay a total of approximately $335,000 in the form of a 50% drilling carry of certain CONSOL Energy working interest obligations as the acreage is developed. As of December 31, 2014, Hess’ remaining carry obligation is $99,474.

CNX Gas Company is party to a joint development agreement with Noble Energy, Inc. (Noble) with respect to approximately 702 thousand net Marcellus Shale oil and gas acres in West Virginia and Pennsylvania, in which each party owns a 50% undivided interest. Under the agreement, as amended, Noble Energy is obligated to pay a total of approximately $1,846,000 in the form of a one-third drilling carry of certain of CONSOL Energy’s working interest obligations as the property is developed, subject to certain limitations. These limitations include the suspension of the carry if average Henry Hub natural gas prices are below $4.00 per million British thermal units (MMbtu) for three consecutive months. The carry was in effect from March 1, 2014, and remained effective until November 1, 2014 when average natural gas prices had been below $4.00/MMbtu for the three prior months and continues to be suspended. Restrictions also include a $400,000 annual maximum on Noble Energy's carried cost obligation. As of December 31, 2014, Noble Energy’s remaining carry obligation is approximately$1,627,065.