MINING PROPERTIES

Mining properties consist of the following (in thousands):



December 31, 2017	Palmarejo			Rochester			Silvertip		Kensington			Wharf				La Preciosa		Total
Mine development	$	214,383		$	193,881		$	57,214	$	298,749		$	40,618			$	—	$	804,845
Accumulated amortization	(146,598		)	(144,390		)	—		(178,632		)	(15,748		)		—		(485,368		)
	67,785			49,491			57,214		120,117			24,870				—		319,477
Mineral interests	629,303			—			245,116		—			45,837				49,085		969,341
Accumulated amortization	(435,215		)	—			—		—			(24,034		)	—	—		(459,249		)
	194,088			—			245,116		—			21,803				49,085		510,092
Mining properties, net	$	261,873		$	49,491		$	302,330	$	120,117		$	46,673			$	49,085	$	829,569



December 31, 2016	Palmarejo			Rochester			Kensington			Wharf			La Preciosa		Joaquin		Other			Total
Mine development	$	174,890		$	165,230		$	271,175		$	37,485		$	—	$	—	$	—		$	648,780
Accumulated amortization	(134,995		)	(138,244		)	(154,744		)	(11,699		)	—				—			(439,682		)
	39,895			26,986			116,431			25,786			—		—		—			209,098
Mineral interests	629,303			—			—			45,837			49,085		10,000		37,272			771,497
Accumulated amortization	(381,686		)	—			—			(19,249		)	—		—		(29,370		)	(430,305		)
	247,617			—			—			26,588			49,085		10,000		7,902			341,192
Mining properties, net	$	287,512		$	26,986		$	116,431		$	52,374		$	49,085	$	10,000	$	7,902		$	550,290

Palmarejo is located in the State of Chihuahua in northern Mexico and consists of the Palmarejo mine and mill, the Guadalupe underground mine, the Independencia underground mine, and other deposits and exploration targets. Palmarejo commenced production in April 2009.

The Rochester silver and gold mine, located in northwestern Nevada has been operated by the Company since September 1986. The mine utilizes heap-leaching to extract both silver and gold from ore mined using open pit methods.

The Silvertip is a silver-zinc-lead mine located in northern British Columbia, Canada. Silvertip is expected to commence production in the first quarter of 2018.

The Kensington mine is an underground gold mine and consists of the Kensington and adjacent Jualin properties located north-northwest of Juneau, Alaska. The Company commenced commercial production in July 2010.

The Wharf gold mine is an open pit gold mine located near the city of Lead, South Dakota. The Company acquired Wharf in February 2015.

The La Preciosa silver-gold project is located in the State of Durango in northern Mexico. The Company completed a feasibility study in 2014 and has deferred construction activities until expected returns improve.

Asset Sales

In February 2017, the Company sold the Joaquin silver-gold exploration project for consideration of $27.4 million and a 2.0% NSR royalty on the Joaquin project, the Company recognized a $21.1 million pre-tax gain on this sale, included in Other, net on the Consolidated Statements of Comprehensive Income.

In July 2017, the Company sold the Endeavor Silver Stream and our remaining portfolio of royalties to Metalla for total consideration of $13.0 million comprised of $6.3 million of Metalla shares and a $6.7 million convertible debenture. The Company recognized a $1.2 million pre-tax gain, included in Other, net on the Consolidated Statements of Comprehensive Income.

In December 2017, the Company entered into an agreement to sell Manquiri, which operates the San Bartolomé mine. See Note 22 -- Held for Sale for additional detail.