Leagold Mining has started portal development for the 1,325m long exploration ramp at the Bermejal underground deposit in Mexico after completing surface preparation.
The ramp is expected to provide access to the high-grade mineralisation of the deposit.
In addition, the ramp is aimed at enabling further exploration, assessing the feasibility of mining the deposit, and advancing the project towards declaration of reserves.
Leagold Mining CEO Neil Woodyer said: "We have been steadily advancing the development of the Bermejal underground as an expansion project at our Los Filos mine, and the start of the portal and ramp is a significant achievement within our initial six months of ownership.
"The contribution from underground mining at Bermejal will add approximately 150,000oz per year to the operation and bring the combined production rate to 350,000oz per year once fully operational."
According to the company, the portal is situated in carbonate rocks on the north side of the mined-out portion of the Bermejal open-pit.
The company earmarked a capital budget of $13m to undertake an aggregate of 3,136m of ramp and cross-cut development, as well as two ventilation raises totalling 560m that will be developed using a bore.
An environmental permit was secured for the mine portal and exploration ramp in July this year.
The company noted that more than half of the drilling programme at the Bermejal underground deposit has been completed with 28,846m drilled of the planned 56,000m.
The entire drilling programme is scheduled to be completed within this year.
Image: The portal location prior to the start of development. Photo: courtesy of Leagold Mining Corporation.