The Concepcion del Oro district has a long mining history.  Mining in this area was primarily focused on precious metals. Until 1889, when the Mazapil Copper Company Ltd. (“Mazapil Copper”) of England, acquired the old mines, and mining expanded to include production of copper and zinc. In 1962, Mazapil Copper ceased operations on the property. Various companies have explored and operated the Aranzazu Project since then.

In June 2008, Aura Minerals assumed operating control of the Aranzazu Project.  The mine had restarted in August 2007 at a limited throughput of approximately 600 tonnes per day. From June 2008 to Decmeber 2008, Aura Minerals took underground production up to 1,200 tonnes per day. Underground development is currently underway to allow a re-start of operations in the second quarter of 2010 at approximately 2,600 tonnes per day. The mining method will be dominantly long-hole stoping, with some minor cut and fill stoping.  Long-hole stoping is capable of achieving relatively high production rates due to high productivity. The planned long-hole stoping will require backfill with binder in order to achieve 100% extraction.  Lower strength backfill, with little or no cement, will be required for the cut and fill stoping areas.