Gold Resource Corporation Updated Mineral Reserve Substantially Increases Oaxaca Mining Unit’s Mine Life

COLORADO SPRINGS, Colo., March 08, 2018 (GLOBE NEWSWIRE) -- Gold Resource Corporation (NYSE American:GORO) (the “Company”) today announced as of December 31, 2017, it increased proven and probable reserve tonnes by 32%, extending its Oaxaca Mining Unit’s mine-life. Gold Resource Corporation is a gold and silver producer, developer and explorer with operations in Oaxaca, Mexico and Nevada, USA. The Company has returned $110 million to shareholders in monthly dividends since commercial production commenced July 1, 2010 and offers shareholders the option to convert their cash dividends into physical gold and silver and take delivery.

Proven and probable reserves at the Oaxaca Mining Unit totaled 2,501,100 tonnes grading 1.77 grams per tonne (g/t) gold and 136 g/t silver, equating to 142,400 gold ounces and 10,927,900 silver ounces. Proven and probable reserve tonnes included in the December 31, 2017 reserve report increased year-over-year by 32%, gold ounces decreased by 15% and silver ounces increased by 9%. The reserve report also includes significant base metals from the Arista Mine consisting of 7,263 tonnes (16.0 million pounds) of copper grading 0.3%, 33,894 tonnes (74.7 million pounds) of lead grading 1.4% and 111,366 tonnes (245.5 million pounds) of zinc grading 4.6%. Proven and probable tonnes of copper increased year-over-year by 31%, lead increased by 41%, while zinc tonnes increased by 67%.

The Company reported 2.42 million proven and probable tonnes from the Arista Mine. Proven and probable tonnes at the Arista Mine increased 31% year-over-year, as a significant portion of the Switchback vein system’s mineralized material was upgraded to the proven and probable category by mine development during 2017. The Company also reported proven and probable reserves at its Alta Gracia Project’s Mirador Mine totaling 80,100 tonnes grading 0.69 g/t gold and 348 g/t silver, equating to 1,800 gold ounces and 897,500 silver ounces. Proven and probable reserve tonnes at the Mirador Mine increased 83% year-over-year.

In addition to, and separate from, the Oaxaca Mining Unit’s proven and probable reserves, 1,790,900 tonnes of measured and indicated mineralized material was reported from three separate mineralized zones. The Arista Mine reported mineralized material of 1,685,800 tonnes grading 1.51 g/t gold, 104 g/t silver, 0.3% copper, 1.2% lead and 3.7% zinc. The Company also reported mineralized material at the Alta Gracia Project of 47,200 tonnes grading 0.66 g/t gold and 258 g/t silver. Finally, the Margaritas property reported mineralized material of 57,900 tonnes grading 0.72 g/t gold and 276 g/t silver.

“We are very pleased to release the December 31, 2017 reserve report showing significant increases to reserve tonnes,” stated Mr. Barry Devlin, Vice President of Exploration for Gold Resource Corporation. “Much of the 2017 reserve ore tonnage and base metal increases came from deep in the Switchback vein system in the same areas as the deepest mine development levels to date. We estimate this area to have lower precious metal grades and higher base metal grades relative to higher elevations in this epithermal vein system. This belief is in line with geologic models and mineral zonation relative to elevation in epithermal vein systems. Our drill results in higher elevations at Switchback so far demonstrate higher precious metal grades are possible. Exploration goals for 2018 include step-up drilling the Switchback vein system at higher elevations, which we believe may contain higher grades of precious metals as we have witnessed historically mining the upper portions of the Arista vein system.”

“This is the strongest Oaxaca Mining Unit reserve report our Company has recorded to date from a tonnage perspective, significantly increasing the proven and probable mine-life of our Mexican operations,” stated Mr. Jason Reid, President and CEO of Gold Resource Corporation. “We now have an estimated proven and probable mine-life of over 4.5 years, an increase of a full year from the year-end 2016 reserve report. This is the fifth annual reserve report that Company has published for its Oaxaca Mining Unit, where it has successfully increased the proven and probable reserve tonnes in each consecutive year. In 2017, we successfully converted mineralized material into proven and probable reserves while still holding 1.8 million tonnes of mineralized material in which we target future reserve conversion. 2017 also saw over 325 meters of Switchback strike length expansion, much of which is not included in current reserve estimates, and exploration efforts announced in 2018 are off to a strong start, as the Company recently reported a 300-meter step-out strike expansion to the Switchback vein system, also not included in the 2017 reserve. We took the last 15 months entering and developing the known bottom of this exciting vein system. We now have five levels of mine development from the twenty-seventh level up to the twenty-third level. If history is our guide, we look for future additions in both tonnage and grade as we explore and mine upwards on this large epithermal vein system within the expanding Arista Mine.”


OAXACA MINING UNIT PROVEN AND PROBABLE RESERVES
As of December 31, 2017

	Description	Tonnes	Gold g/t	Silver g/t	Precious Metal Gold Equivalent g/t	Gold Ounces	Silver Ounces	Precious Metal Gold Equivalent Ounces	Copper %	Lead %	Zinc %
	*Arista Mine*
	Proven	1,987,600	1.87	130	3.64	119,800	8,299,800	232,600	0.3	1.5	4.6
	Probable	433,400	1.50	124	3.19	20,800	1,730,600	44,400	0.3	1.4	4.5
	*Arista Mine Total*	2,421,000	1.81	129	3.56	140,600	10,030,400	277,000	0.3	1.4	4.6
	*Mirador Mine*
	Proven	59,400	0.71	352	5.49	1,400	672,600	10,500
	Probable	20,700	0.65	337	5.23	400	224,900	3,500
	*Mirador Mine Total*	80,100	0.69	348	5.43	1,800	897,500	14,000
	Oaxaca Mining Unit Total	2,501,100	1.77	136	3.62	142,400	10,927,900	291,000

Metal prices used for P & P reserves were $1,222 per ounce of gold, $16.62 per ounce of silver, $2.50 per pound of copper, $0.90 per pound of lead and $1.05 per pound of zinc. These prices reflect the three-year trailing average prices for gold, silver, copper, lead and zinc.
Precious metal gold equivalent is 73.53:1 using gold and silver only to calculate gold equivalencies.
A breakeven Net Smelter Return (NSR) cutoff grade of $80 per tonne was used for estimations of P & P reserves at the Arista Underground Mine. The term “cutoff grade” means the lowest NSR value considered economic to process.
No appreciable amounts of base metals are present in the veins identified to-date at the Mirador Underground Mine at the Alta Gracia property. A breakeven cutoff grade of 2.04 g/t gold-equivalent (AuEq) was used for proven and probable reserves at the Mirador Underground Mine using gold and silver only to calculate gold equivalencies.
Mining, processing, energy, administrative and smelting/refining costs were based on 2017 actual costs for the Oaxaca Mining Unit.
Arista Mine metallurgical recovery assumptions used were 81% for gold, 92% for silver, 73% for copper, 74% for lead and 84% for zinc. Mirador Mine metallurgical recovery assumptions used were 74% for gold and 81% for silver. These recoveries reflect 2017 actual average recoveries for the Aguila and Alta Gracia Projects.
P & P reserves are diluted and factored for expected mining recovery.
Minimum mining width for P & P reserves is 1.5 meters.
Figures in tables are rounded to reflect estimate precision and small differences generated by rounding are not material to estimates.


OAXACA MINING UNIT MEASURED AND INDICATED MINERALIZED MATERIAL
As of December 31, 2017

	Description	Tonnes	Gold g/t	Silver g/t	Copper %	Lead %	Zinc %
	*Arista Mine*
	Measured	677,100	1.55	112	0.3	1.2	3.9
	Indicated	1,008,700	1.49	99	0.2	1.2	3.6
	*Arista Mine Total*	1,685,800	1.51	104	0.3	1.2	3.7
	*Alta Gracia Project*
	Measured	23,300	0.74	275
	Indicated	23,900	0.58	241
	*Alta Gracia Project Total*	47,200	0.66	258
	*Margaritas Project*
	Measured	19,800	0.70	280
	Indicated	38,100	0.73	274
	*Margaritas Project Total*	57,900	0.72	276
	Oaxaca Mining Unit Total	1,790,900

Metal prices used for Measured and Indicated (M & I) mineralized material were $1,222 per ounce of gold, $16.62 per ounce of silver, $2.50 per pound of copper, $0.90 per pound of lead and $1.05 per pound of zinc. These prices reflect the three-year trailing average prices for gold, silver, copper, lead and zinc.
A breakeven Net Smelter Return (NSR) cutoff grade of $80 per tonne was used for estimations of M & I mineralized material. The term “cutoff grade” means the lowest NSR value considered economic to process.
No appreciable amounts of base metals are present in the veins identified to-date at the Alta Gracia Project including the Mirador Underground Mine, and the Margaritas Project. A breakeven cutoff grade of 2.04 g/t gold-equivalent (AuEq) was used for M & I mineralized material at the Alta Gracia and Margaritas Projects using gold and silver only to calculate gold equivalencies.
Arista Mine metallurgical recovery assumptions used were 81% for gold, 92% for silver, 73% for copper, 74% for lead and 84% for zinc. Alta Gracia and Margaritas projects metallurgical recovery assumptions used were 74% for gold and 81% for silver. These recoveries reflect 2017 actual average recoveries for the Aguila and Alta Gracia Projects.
M & I mineralized material is diluted and factored for expected mining recovery.
Minimum mining width for M & I mineralized material is 1.5 meters.
Figures in tables are rounded to reflect estimate precision and small differences generated by rounding are not material to estimates.

The full reserve report will be available in the near future from the Company’s website using the following link: http://goldresourcecorp.com/reserve-reports.php

About GRC:

Gold Resource Corporation is a gold and silver producer, developer and explorer with operations in Oaxaca, Mexico and Nevada, USA. The Company targets low capital expenditure projects with potential for generating high returns on capital. The Company has 57,107,884 shares outstanding, zero warrants and has returned $110 million back to shareholders since commercial production commenced July 1, 2010. Gold Resource Corporation offers shareholders the option to convert their cash dividends into physical gold and silver and take delivery. For more information, please visit GRC’s website, located at www.goldresourcecorp.com and read the Company’s 10-K for an understanding of the risk factors involved.

Cautionary Statements:
This press release contains forward-looking statements that involve risks and uncertainties. The statements contained in this press release that are not purely historical are forward-looking statements within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act. When used in this press release, the words “plan”, “target”, "anticipate," "believe," "estimate," "intend" and "expect" and similar expressions are intended to identify such forward-looking statements. Such forward-looking statements include, without limitation, the statements regarding Gold Resource Corporation’s strategy, future plans for production, future expenses and costs, future liquidity and capital resources, and estimates of mineralized material. All forward-looking statements in this press release are based upon information available to Gold Resource Corporation on the date of this press release, and the company assumes no obligation to update any such forward-looking statements. Forward looking statements involve a number of risks and uncertainties, and there can be no assurance that such statements will prove to be accurate. The Company's actual results could differ materially from those discussed in this press release. In particular, there can be no assurance that production will continue at any specific rate. Factors that could cause or contribute to such differences include, but are not limited to, those discussed in the Company’s 10-K filed with the SEC.

Contacts:
Corporate Development
Greg Patterson
303-320-7708
www.goldresourcecorp.com


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