The Pinos Altos mine is in the northern part of the Sierra Madre geologic province, on the northeast margin of the Ocampo Caldera, which hosts many epithermal gold and silver occurrences, including the nearby Ocampo and Moris mines.

The property is underlain by Tertiary-age (less than 45 million years old) volcanic and intrusive rocks that have been disturbed by faulting. The volcanic rocks belong to the lower volcanic complex and the discordant overlying upper volcanic supergroup. The lower volcanic complex is represented on the property by the Navosaigame conglomerates (including thinly-bedded sandstone and siltstone) and the El Madrono volcanics (felsic tuffs and lavas intercalated with rhyolitic tuffs, sandy volcanoclastics and sediments). The upper volcanic group is made up of the Victoria ignimbrites (explosive felsic volcanics), the Frijolar andesites (massive to flow-banded, porphyritic flows) and the Buenavista ignimbrites (dacitic to rhyolitic pyroclastics).

Intermediate and felsic dykes as well as rhyolitic domes intrude all of these units. The Santo Nino andesite is a dyke that intrudes along the Santo Nino fault zone.

Structure on the property is dominated by a ten-kilometre by three-kilometre horst, a fault-uplifted block structure oriented west-northwest, that is bounded on the south by the south-dipping Santo Nino fault and on the north by the north-dipping Reyna de Plata fault. Quartz-gold vein deposits are emplaced along t ........

Commercial production was achieved at the Pinos Altos mine in November 2009 and, under current mine plans, the mine is expected to be in production through 2027. A shaft sinking project was completed in June 2016 at the Pinos Altos mine and during 2018, the site transitioned into being a predominantly underground mining operation.

The underground mining method is sublevel stoping (paste backfill) to extract ore from the Santo Niño, Cerro Colorado and Oberon de Weber deposits.

At the Cubiro deposit, underground development advanced by 322 metres in the fourth quarter of 2021 and by 2,743 metres for the full year of 2021. Work remains ahead of forecast. Construction of the powerline was completed in the fourth quarter of 2021. Pre-production activities will continue through 2022 into 2023. Initial production is expected in the second half of 2023. Once completed, Cubiro is expected to provide additional production flexibility to the Pinos Altos operations.

At Sinter, a trench was mined at the bottom of the depleted pit, contributing 32,000 tonnes in the fourth quarter of 2021. Production from the Sinter deposit is now from underground operations. The pastefill plant and the ventilation system are approximately 90% complete and are expected to be commissioned in the first quarter of 2022. Sinter underground is expected to ramp-up to its full production capacity in the first half of 2022.

At Reyna de Plata, site preparation activitie ........

Ore from the Pinos Altos mine is treated by one of two processes: conventional processing in a mill for higher-grade ore; and a minor amount of heap-leaching for lower grade ore.

The conventional, 5,500-tonnes/day processing plant includes crushing, grinding, gravity concentration and agitated leaching followed by counter-current decantation. During 2017, the Company commissioned a silver flotation plant, which has increased overall silver recovery to an average of 22% in the flotation plant. Gold and silver are recovered using the Merrill-Crowe method, and a refinery produces gold/silver doré bars on site. Metals recovery in the plant averages approximately 94% for gold and 58% for silver.

In 2019, the Company began testing samples from Pinos Altos and La India at an ore sorting pilot plant at Pinos Altos, with favourable preliminary results. Similar ore sorting pilot testing has been considered at the Company's other operating sites.