http://www.argonautgold.com/news_events/news/news_release/index.php?&content_id=354

oronto, Ontario – (September 21, 2017) Argonaut Gold Inc. (TSX: AR) (the “Company”, “Argonaut Gold” or “Argonaut”) is pleased to provide updated pit-constrained Mineral Resource estimates for its operating mines. The updated Mineral Resource estimates are net of mining depletion at July 1, 2017 and incorporate recent resource expansion drilling at both El Castillo and La Colorada (see press releases dated March 20, 2017, May 8, 2017 and June 1, 2017). All dollar amounts are expressed in United States dollars unless otherwise specified.

El Castillo Mineral Resource Estimates⁽¹⁾

¹The pit-constrained M&I Mineral Resource and Inferred Mineral Resource for El Castillo in the above table were updated internally, are valid as of July 1, 2017 and were reviewed by Michael Lechner, who is a “qualified person” for purposes of NI 43-101. The Mineral Resources update used a gold price of $1,400. Cut-off grades, depending on rock and ore type, varied from 0.093 g/t for oxide to 0.467 g/t for silicified sulphide. Mineral Resources do not have demonstrated economic viability. There is no certainty that all or any part of the Mineral Resources will be converted into Mineral Reserves. Numbers may not sum exactly due to rounding.

At December 31, 2016, pit-constrained M&I Mineral Resources at El Castillo totalled approximately 486,000 contained gold ounces.  Through the acquisition of the adjacent San Juan concession in February 2017 and the subsequent resource expansion drilling programs, the Company added approximately 328,000 gold ounces bringing the M&I Mineral Resources to approximately 814,000 gold ounces.  Between December 31, 2016 and July 1, 2017, the Company depleted approximately 63,000 gold ounces through mining activities leaving M&I Mineral Resources of approximately 751,000 contained gold ounces at El Castillo at July 1, 2017.

La Colorada Mineral Resource Estimates⁽²⁾

²The pit-constrained Indicated Mineral Resource and Inferred Mineral Resource used for La Colorada in the above table were updated internally, are valid as of July 1, 2017 and were reviewed by Michael Lechner, who is a “qualified person” for purposes of NI 43-101. The Mineral Resources update used a gold price of $1,400 and a silver price of $20. The gold equivalent cutoff grade varied depending on deposit and ranged from 0.085 g/t to 0.118 g/t. Mineral Resources do not have demonstrated economic viability. There is no certainty that all or any part of the Mineral Resources will be converted into Mineral Reserves.