Gold Resource Corporation's Arista underground mine is located at the Company's El Aguila Project in the southern state of Oaxaca, Mexico. The El Aguila Project mineralization occurs as structurally-controlled epithermal deposits in veins and stockwork zones consisting of concentrations of sulfides containing gold, silver, copper, lead and zinc, associated with gangue minerals such as quartz, calcite, and other minor elements.

Development of the Arista mine began in 2009, and initial production from the deposit began in March 2011. Ore is trucked approximately two kilometers to the Aguila mill where it is processed into three differential concentrates: a copper/gold; a lead/silver; and a zinc.

Since the initial discovery of the Arista and Baja veins in 2007, multiple additional en echelon veins have been discovered, many which have been mined or will be mined in the future. The Arista deposit is currently "open" in both strike and at depth, and consists of two distinct vein systems – the Arista and the Switchback. The Company continues to drill the extensions of the Arista deposit to extend the mine life.

For the latest Arista resource report, please visit the "Reserves" section of the website.

For the latest models of the Arista deposit, please view the latest corporate presentation

Gold Resource Corporation currently processes all of the Arista underground mine ore through the flotation circuit at the Company's El Aguila mill. The plant was built near the mine site and consists of two separate production circuits: a differential flotation circuit (sulphide ores) and an agitated leach circuit (oxide ores). The current nominal capacity of the flotation circuit is 1,800 tonnes per day, while the agitated leach circuit has a nominal capacity of 300 tonnes per day.

The flotation circuit produces three types of high-grade concentrates: a copper concentrate with gold-silver; a lead concentrate with gold-silver; and a zinc concentrate with gold-silver. All concentrates are marketed to a broker in México.

The Aguila plant's agitated leach circuit is currently idle as the Company evaluates long-term sources of oxide ore.

Gold Resource Corporation's Mirador underground mine is located at the Company's Alta Gracia Project in the southern state of Oaxaca, Mexico. Oxide mineralization from the Mirador mine is trucked to and processed in the Aguila Mill's agitated leach circuit. Initial mining rates target 100 to 200 tonnes per day and an initial mill processing rate of 150 tonnes per day. The Mirador mine has the potential to increase the Company's future annual silver production by approximately 500,000 silver ounces and 1,000 gold ounces.