The host rocks at Creston-Mascota are the Frijolar Andesite and the Victoria Ignimbrite units. Generally shallowly west-dipping quartz-calcite veins and stockwork zones of mineralization associated with the Creston-Mascota deposit can be followed on the surface over a distance of 1000 metres north-south and vary in thickness from 4 to 30 metres. The West Fault, first recognized during the 2008 drilling program at Creston-Mascota, is a sub-vertical, North-South striking feature against which the Creston-Mascota deposit terminates in the down-dip direction. It has been interpreted as a mainly post-mineral fault that offsets the Creston-Mascota deposit from its down-dip continuation, thought to be represented by mineralization observed at the Bravo mine/Carola prospect, located immediately southwest of Creston-Mascota. In the mineralized zone at Creston-Mascota, quartz-calcite veining is developed in the form of stockwork or as breccia (replacement and open space filling breccia sub-unit). In some locations, moderate stockwork veining, zones of silicification, and anomalous gold values also occur along the West Fault, whereas elsewhere, the West Fault consists only of nonmineralized clay gouge and breccia.

Creston Mascota is an open-pit, heap-leach facility 7 kilometres northwest of the Santo Niño pit. It mines an average of 5,500 tonnes of ore per day and employs the same surface mining method as Pinos Altos. Mining is by conventional open pit methods, using shovels and trucks.

All the Creston Mascota ore is processed using heap-leaching. The 4,000-tonne-per-day heap leach facility at Creston Mascota is similar to the Pinos Altos facility, but the precious metals are recovered by a small carbon column circuit. The gold and silver is stripped from the carbon in the Pinos Altos plant and then poured as doré bars, with expected ultimate gold recoveries of 65% and 16% for silver when leaching is completed.