Name of the Project
Bunker Hill zinc/lead/silver mine restart project.

Location
Silver Valley, Idaho, in the US.

Project Owner/s
Bunker Hill Mining Corp.

Project Description
Bunker Hill is a historic past-producing zinc, lead and silver mine. 

The mine produced 42.77-million tons of ore over its operating history, at average grades of 8.43% lead, 4.52% zinc and 3.52 oz/t silver.

The restart is based on a phased redevelopment of the mine, with an initial target throughput of 1 800 t/d. The 2022 prefeasibility study outlined an initial five-year life-of-mine, based on the Phase 1 mine plan.

The Phase 1 mine plan envisages zinc-equivalent production of 475-million pounds at a zinc-equivalent grade of 8.5%, comprising 317-million pounds of zinc, 146-million pounds of lead and 3-million ounces of silver.

Bunker Hill plans to use longhole stoping as the primary underground mining method. The mine will be accessed through the enlarged and refurbished Russell portal, which connects to a newly built internal ramp extending about 3 km from the 4 Level to the 9 Level and the Kellogg tunnel. Paste backfill will be used, supported by the company’s tailings filtration plant, to reduce the volume of tailings requiring surface storage.

Phase 2 opportunities include resource conversion, potential resource expansion, further increases in scale, ongoing metallurgical optimisation and ore sorting.

Potential Job Creation
Not stated. 

Net Present Value/Internal Rate of Return
The 2022 PFS estimated an after-tax net present value, at an 8% discount rate, of $52-million and an internal rate of return of 36%, with a payback of 2.1 years. 

Capital Expenditure
In January 2026, Bunker Hill reported that it had completed a comprehensive refinancing package that extended debt maturities to 2030, reduced outstanding debt by about 39%, lowered the effective cost of capital by reducing royalty and stream obligations from 11.85% to 5%, and secured incremental funding of $68-million to fully finance the remaining project milestones.

Planned Start/End Date
Bunker Hill remains on track to restart operations and start production in June 2026. The company expects sustainable free cash flow in the second half of 2026.

Latest Developments
Bunker Hill reported on May 4 that the restart of operations remained on track for June 2026, with about 93% of preproduction activities complete. Underground development, infrastructure readiness and equipment commissioning were progressing as planned.

The company also announced initial results from the underground exploration drill programme under way on the Cate-Eight target at the mine. Drillhole BHE26-01 intersected two new high-grade silver/lead veins close to existing underground infrastructure. The company reported that the mineralisation occurs within 40 ft to 120 ft of mine development and remained open for expansion in all directions.

The Cate-Eight target is the first target being tested in the multitarget 2026 exploration drill programme. 

By early May, about 730 ft of the planned 25 000 ft campaign had been drilled. The programme is intended to test high-grade silver targets near recently constructed mine infrastructure, with the potential for successful targets to be incorporated into the near-term production plan.

Key Contracts, Suppliers and Consultants
Timberline Drilling (drilling campaign); Caterpillar Inc (new underground mining fleet); and Metso (tailings filter press installation).

Contact Details for Project Information
Bunker Hill Mining Corp, email ir@bunkerhillmining.com.