Primero was formed in 2007 as a junior precious metals exploration company (Mala Noche Resources) listed on the TSX Venture exchange. Upon acquisition of the San Dimas mine in August 2010 it became a producer and changed its name to Primero Mining Corp. Some of the key events in Primero’s or San Dimas' history include:

1757 First reported mining on San Dimas deposit

1904 Tayoltita mill built at San Dimas

1940 San Luis Mining Company acquired San Dimas property

1961 Minas de San Luis S.A. de C.V. formed, acquired 51% and assumed San Dimas operations

1978 Luismin S.A. de C.V. acquired remaining 49% of San Dimas

2002 Wheaton River Minerals Ltd. acquired San Dimas

2003 Tayoltita Mill expansion to 1,600tpd

2005 Wheaton River merged with Goldcorp Inc.

2004 Wheaton River entered into silver purchase agreement, selling all silver from San Dimas at ~ $4 per ounce.

2006 Tayoltita Mill expansion to 2,100tpd

2007 Mala Noche Resources incorporated and began trading on TSX Venture:MLA

2010 Acquired 100% of the San Dimas mine
Changed name to Primero Mining Corp
Amended silver perchace agreement, gaining exposure to silver above minimum thresholds. Primero began trading on TSX:P

2011 Primero began trading on NYSE:PPP