A Pivot to Silver

A new team focused on the exploration and sustainable development of the mine’s untapped silver potential

The Bunker Hill Mining Corporation has the exclusive lease and option to purchase the Bunker Hill Mine - a large scale resource and patented land package located in Northern Idaho’s prolific Silver Valley.

For near a century from 1885, the Bunker Hill Mine and its associated electrolytic zinc processing plant and lead smelter was one of the most productive mining operations in the United States of America. With its primary purpose being the generation of a zinc concentrate from 1927 it produced 35 million tons of ore in concentrates, with an average grade of 8.76% Lead, 3.67% Zinc and 5.49 oz/t Silver. Significantly, this included a total of 165Moz of Silver.

Closed in 1981 due to the coincident effect of low base metal prices and the need to invest significant capital in the upgrade of its processing and smelting operations to meet new environmental regulations, it has remained on care and maintenance ever since. Following its closure, and as part of a regional environmental clean-up operation run by the US Government, its lead smelter and zinc processing plant have been fully dismantled, and its water discharge treated by a government-run Water Treatment Facility.

With the arrival of a new leadership team in 2020 with the intent to verify, explore and develop its untapped higher-grade silver potential using the most modern analytical, exploration, mining and processing techniques the mine is poised for a second profitable and environmentally sustainable life.


165Moz of Silver in 95 years

For nearly a century, the Bunker Hill Mine, was one of the most productive mines in the highly prolific Silver Valley region of the Coeur d’Alene Mining District. A region that includes many world-renowned silver mines such as the Lucky Friday, Gold Hunter, Sunshine, Galena and Crescent mines, and one that produced over 1.2Bn Oz of Silver in its history.

Primarily focused on the production of zinc and lead concentrates from the mining of over 30 distinct and often-disseminated Sphalerite (zinc-rich) or over 10 distinct narrower and higher-grade Argentiferous-Galena (lead-silver rich) and other hybridised veins, it nonetheless produced 165Moz of silver as a valuable by-product. Significantly, this silver represented over 31% of the mine’s gross metal value, and 40-50% of its Net Smelter Value over that time.

Following the construction of its lead smelter in 1920 and its electrolytic zinc processing plant in 1927 its mining operations were focused on maintaining the maximum possible ore-feed to these expensive downstream components of the business value-chain to ensure optimal profitability. This mining focus of volume over grade, led to extensive use of bulk-mining techniques within the largest zinc ore-bodies from the 1960s and a corresponding significant reduction in head grade by the 1970s. A volume-focused business model that became untenable when metal prices collapsed due the effects of the global recession that followed the 1973 Oil Crisis and the collapse of the Bretton Woods system.

From 1977, as an attempt to improve its long-term profitability, the mine owners conducted the first systematic survey of the mine’s geology in the mine’s history in order to inform an exploration and mine development plan that would focus on generating the highest head-grade for the processing plants as possible. These studies yielded significant new insights and indicated new opportunities for the business as well as highlighting the strategic importance of its silver endowment as a central to the mine’s future profitability. Sadly, the benefit of these new insights was never realised, as the mine was closed in 1981.

  • Produced 165Moz of Silver as a by-product to Zinc and Lead focused mining.
  • Silver represented 40-50% of the Net Smelter Value of the operation over its history.
  • Following the first systematic review of its geology in the late 1970s the mine started a strategic pivot towards its silver endowment but was shut down in 1981 before the benefits of this pivot could be realised.



A focus on Silver, Partnerships, and Modernisation

Led by Sam Ash, our new CEO, an American mining engineer who is himself the son of a Bunker Hill employee from the 1970s, the company is focused on identifying the optimal development strategy for the mine.

This involves four key activities:

  • Compilation and Digitisation of all mine data focused on compiling 95 years of data including that collected from over 3500 drill holes and the strategic insights developed in the 1970s to build a modern 3D geological and mine model to inform strategic planning.
  • Silver-focused exploration drilling from underground and the surface combined with sampling the open stopes. This is focused initially on the targets above the existing water level and close to existing infrastructure to build a high-value silver resource inventory.
  • Long-Term Water Management focused on working with the Environmental Protection Agency (EPA) the Idaho Department of Environmental Quality (IDEQ) and other stakeholders to ensure the optimal long-term water management plan for the mine.
  • Stakeholder engagement focused on building new relationships with the many stakeholders associated with the mine and its environment to ensure they all benefit from and support the future development plans.



Head Office – Toronto, Ontario


Bunker Hill Mine – Silver Valley, Idaho