Drilling Campaign Doubles Target Size of the Cate-8 Discovery Target

Intersects Highest Grades Yet With 8.1 Feet at 18.82 oz/ton Silver in BHE26-16, Individual Samples to 27.1 oz/ton Silver, 35.7% Lead, 15.7% Zinc

Targeting Initial Cate-8 Resource Estimate by Year-End 2026

KELLOGG, Idaho and VANCOUVER, British Columbia, July 15, 2026 (GLOBE NEWSWIRE) — Bunker Hill Mining Corp. (“Bunker Hill” or the “Company”) (TSX: BNKR | OTCQB: BHLL) is pleased to announce additional assay results from its ongoing underground exploration drilling program in the upper part of the Bunker Hill mine (the “Bunker Hill Mine”), including individual sample grades up to 27.3 oz/ton silver, 35.7% lead and 15.7% zinc, with combined silver-equivalent metal grades up to 32.9 oz/ton or 1,128 g/t AgEq (see below for calculations).

“As we progress towards expected commercial production by the end of 2026, we are increasingly excited by the results of the 21 holes drilled to date. The continuity and scale of mineralization encountered is beyond the boundaries of the existing resource footprint,” said Sam Ash, President and Chief Executive Officer of Bunker Hill Mining. “From here, additional drilling will be required, as we aim to establish an additional zone of mineralization that can supplement the current production profile, and we believe that the success achieved to date positions us well to deliver an initial resource estimate before year-end, with the potential for inclusion in our production plan and full-year guidance for 2027.”

New drill results continue to demonstrate silver-lead grades and thicknesses in siderite-galena (sphalerite) veins comprising the Cate-8 Vein Target (the “Cate-8 Target”). These are expected to support the completion of an initial mineral resource estimate for the zone by the end of 2026. Geologic modeling of the drill results has shown the Cate-8 Target is a different hybrid vein type than the narrow Galena-Quartz veins initially targeted and is not cut off at depth by the regional Cate Fault (the “Cate Fault”), both of which may increase potential tonnages and contained metal values of the Cate-8 Target.  

Updated modeling of the Cate-8 Target supports the concept of a mineralized zone adjacent to current mine development, outside of known resources, with sufficient grades and thickness to be incorporated into near-term mine plans with continued successful exploration results. The Cate-8 Target was recalculated using new drill intercepts across a range of theoretical cut-off grades and shows a potential 100% increase in tonnages and grades compared to previous estimates (details listed below). At a cut-off grade of 50 g/t AgEq, the Cate-8 Target model (the “Cate-8 Target Model”) includes 337k tons at a grade of 6.17 oz/ton AgEq for 2.08M ounces of silver equivalent metal (calculated using only AgEq values, blocks not subdivided by metal values).

Highlights from the drill program include:

• 8.1 feet at 18.82 oz/ton Ag, 8.87% Pb, 0.25% Zn (20.98 oz/ton AgEq) (2.47m at 719.5 g/t AgEq), 6.3 feet at 5.29 oz/ton Ag, 15.23% Pb, 0.87% Zn (9.16 oz/ton AgEq) (1.92m at 314.23 g/t AgEq) and 5 feet at 3.53 oz/ton Ag, 8.96% Pb, 1.38% Zn (6.13 oz/ton AgEq) (1.52m at 210.1 g/t AgEq) in BHE26-16;
• 22.6 feet at 1.64 oz/ton Ag, 5.1% Pb, 1.19% Zn (3.27 oz/ton AgEq) (6.89m at 112.12 g/t AgEq), including 6.8 feet at 2.61 oz/ton Ag, 8.49% Pb, 1% Zn (4.96 oz/ton AgEq) (2.07m at 170 g/t AgEq) in BHE26-13;
• 6.3 feet at 2.74 oz/ton Ag, 5.9% Pb, 0.07% Zn (4.14 oz/ton AgEq) (1.92m at 141.9 g/t AgEq) in BHE26-15;
• Cate-8 Target Model expands from maiden estimate to 337k tons at a grade of 6.17 oz/ton AgEq for 2.08M ounces of contained silver equivalent metal at a cut-off grade of 50 g/t AgEq (calculated using only AgEq values, blocks not subdivided by metal values);
• Multiple galena-siderite veins intercepted within the Cate-8 Target structural corridor, identifying a 10-42 feet thick mineralized zone (true thickness);
• Demonstrated continuity of individual veins and overall mineralized zone for 680 feet along strike and 880 feet down dip;
• Grades and thicknesses continue to support targeting mineralization with the potential to be included in near-term mine plans with continued exploration success;
• Confirmation of hybrid-type mineralization, with discrete zinc and silver-lead veins on the margins of the zone overlapping in the core mineralized shoot of the vein target;
• First drill intercepts of silver-rich, copper-antimony bearing tetrahedrite mineralization in modern exploration at the Bunker Hill Mine. Indicated in logging and pXRF readings, confirmed by recent assay results with very high silver values with low lead grades: 1.2 feet at 27.3 oz/ton Ag, 1.06% Pb, 0.36% Zn in BHE26-13; 5.3 feet (poor recovery) at 20.4oz/ton Ag, 1.77% Pb, 0.136% Zn; and
• Discovery of a new vein in the hanging wall of the Cate Fault above the Cate-8 Target with rounded, zinc-mineralized siderite clasts in a pyrite breccia matrix, up to 13 ft of drilled thickness. This represents an intriguing target, as this type of mineralization was commonly mapped on peripheries of some of the largest historically mined veins.

Chief Geologist Sam Bourque states, “We are focused on unlocking the full potential of the Bunker Hill Mine’s mineral system by testing proven geologic concepts with cutting-edge technology and methods. Prior geologists supplied a wealth of detailed structural and stratigraphic studies and concepts prior to the mine shutting down in 1981; we are the first group that has placed these concepts and the underlying data into modern 3D geologic models. Known post-mineral fault offsets and vein patterns and distribution strongly suggest that even after 90 years of continuous work, mining at the Bunker Hill Mine has only tested one quarter of the original mineralized system. By targeting high-grade silver mineralization both adjacent to existing workings like the Cate-8 Target, and across our broader land package as at the Page project, we’re not only increasing geological confidence for near-term mine planning but also identifying opportunities to potentially expand resources, extend mine life and enhance the long-term value of our broader land package.”

SUMMARY OF NEW DRILL RESULTS

Table 1: New intercepts in recent underground drillholes at the Cate-8 Target

There have been 21 core holes completed to date for a total of 7,350 feet of drilling. All holes have intercepted visible galena (lead sulfide) mineralization, with sphalerite (zinc sulfide) commonly seen along margins of veins. The Cate-8 Target is marked by two to five discrete, 0.5-4.5-foot thick (drilled) galena-siderite-(sphalerite-pyrite) veins, which appear to variably bifurcate and rejoin into thicker veins across an overall mineralized zone ranging from 10-42 feet in modeled true thickness. A higher-grade and thicker shoot of mineralization has been identified within the vein, plunging to the southwest, which matches the structural interpretation of the hybrid mineralization Cate-8 Target. Mineralization thins downdip on the Cate-8 Target to the west, with drillholes BHE26-07, 08 and 09 likely defining the edges of potentially economic mineralization within the zone in that direction.

Due to the polymetallic nature of the hybrid mineralization in the Cate-8 Target, silver-equivalent grades were determined for each sample interval. Silver equivalent grade (AgEq) was calculated using long-term metal price forecasts of US$76.36/troy ounce silver, $0.89/lb lead and $1.41/lb zinc, with recovery rates of 91.6% for silver, 88.6% for lead and 86.8% for zinc (from BHMC 2024 PFS). Using these parameters, the metal equivalent factors are 1% zinc = 12.66 g/t AgEq, and 1% lead = 7.99 g/t AgEq, with total AgEq calculated with the formula:

AgEq g/t=Ag g/t + (Zn% * 12.66) + (Pb% * 7.99)

Notes – Intercepts listed are drilled length; true thickness is unknown from current data and is estimated at 50-60% of drilled length for BHE26-14, 15, 16; 75% for BHE26-11, 12, 13; and 85-95% for BHE26-7, 8, 9, 10. Core recovery was good (>90%) in mineralized zones other than BHE26-14, 15 and 16, which were drilled at low angle to the Cate-8 structure; these intervals will be drilled from a more ideal location on the 7 Level for inclusion in a potential future resource estimate. To avoid coarse versus fine bias in rubble zones and expedite sample processing on resource infill holes, whole core sampling was implemented on holes 10-16. Further infill drilling is planned for the zones from more ideal angles from a drill station on the 7 Level. Half core will be preserved from these holes for metallurgical work and reference material for future resource calculations.

Figure 1: Plan view of drill traces from 8 Level. 100-foot grid, existing development in gray outline

Figure 2: Vertical cross-section of drill hole traces showing intercepts with Ag equivalent grades

DRILL RESULTS CONTINUE TO EXPAND SIZE AND POTENTIAL OF CATE-8 VEIN DISCOVERY

The original exploration concept for the Cate-8 Target was a Galena-Quartz (“GQ”) vein which had been cut and offset within the regional Cate Fault. Mineralization and vein patterns intercepted in drilling have shown that the Cate-8 Target is a hybrid-type vein in the footwall of the Cate Fault, with Bluebird vein zinc mineralization overprinted by GQ vein silver-lead mineralization. This removes a projected structural top and base to the Cate-8 Target where it is currently being explored and increases both the size and the contained metal content of the Cate-8 Target, an analogue being the March stope, which was mined continuously from 1885-1936, producing 4.7M tons at grades of 12% lead, 5.22 oz/ton silver and 2.25% zinc (Bunker Hill Mining Corp. Prefeasibility Study, 2022 (the “Bunker Hill PFS”)).

Figure 3: Vertical long-section of Cate-8 Target with Ag equivalent grades. Current development shown in black outline. Elevation grid is 100-foot spacing.

This recognition of a shared hydrothermal plumbing system provides encouraging exploration corridors to connect the N-NW-striking Cate-8 Target with both NW-striking, shallow-dipping, zinc-rich Bluebird veins and N-NE-striking, steeply dipping, silver-lead-bearing GQ veins. While historical exploration efforts focused on each vein set individually, the structural window between them was largely ignored. A visual assessment of the distribution of historic stopes isolated on either vein set highlights numerous specific locations to look for additional Cate-8 Target type veins near-mine (highlighted in magenta in Figure 4 below).

Figure 4: Vertical section of Bunker Hill Mine (black) showing historic Bluebird (blue shading) vs GQ vein stopes (red shading), and prospective near-mine hybrid vein exploration target areas (magenta shading)

CATE-8 TARGET ESTIMATE

New drill data has been incorporated into the Company’s existing Cate-8 Target Model for the Cate-8 Target (see Bunker Hill’s press release dated June 7, 2026), with a substantial increase in prospective tonnage and grade ranges. The target estimate has been calculated using only drill data with industry standard scripting in Maptek Vulcan 3D software, a 200 ft radius search ellipsoid along strike and dip, and a tonnage factor of 11.38 ft/ton (It should be noted that the tonnage factor used is for zinc dominant mineralization in the Bunker Hill PFS; samples of higher-grade lead-silver galena-siderite veins have had density measurements as high (low) as 6.28 ft³/ton). Due to the polymetallic nature of the hybrid mineralization in the Cate-8 Target, silver-equivalent grades were used to directly assess the overall potential for economic extraction of mineralization in the Cate-8 Target Model. No calculation was performed on the individual metals’ distribution within the block model estimation.

Due to the bifurcating veins and the addition of shoulder samples to infill isolated samples across the structural zone, the entire Cate-8 Target was modelled as a single unit for this iteration. With a wider spacing of intercepts, complete assays across the zone, and substantially higher-grade assays in BHE26-16 than prior holes, tonnage was added to the target estimate, with much of that at higher grade ranges than the prior reported estimates. At a cut-off grade of 50 grams/tonne silver equivalent (AgEq), the Cate-8 Target Model for the Cate-8 Target contains 2.08M ounces of silver-equivalent metal in 337k tons at a grade of 6.17 oz/ton AgEq.

The reader is cautioned that the Cate-8 Target Estimate does not constitute, nor is it implied as, a mineral resource estimate. A qualified person has not done sufficient work on the Cate-8 Target drill data to be incorporated in a Mineral Resource Estimate, and there is no assurance that further exploration work will lead to the definition of any economic mineralization. The potential quantity and grade are conceptual in nature.

Table 2: Tonnage and grade estimates for Cate-8 Target at a range of AgEq cut-off grades

ONGOING DRILLING-PATHWAY TOWARD A POTENTIAL 2026 INITIAL RESOURCE ESTIMATE

Bunker Hill has initiated a focused work program to support the preparation of an initial mineral resource estimate by the end of 2026. 10 additional drill holes have been planned from the current 8 Level drill station, designed to test the margins of the Cate-8 Target and provide internal drill spacing adequate for calculation of a mineral resource estimate at a Measured and Indicated classification level under National Instrument 43-101 – Standards of Disclosure for Mineral Exploration Projects (“NI 43-101”).

An additional drill station is in preparation on the 7 level of the Bunker Hill Mine, which will allow testing of the up-dip projection of the Cate-8 Target. This station will allow for drilling the Cate-8 Target at higher angles, closer to perpendicular, which should greatly improve drill recovery and intact core segments. This will, in turn, allow for a more confident geologic interpretation and resource calculations. Approximately 12 holes are planned from the 7 Level station for a total of ~9,000 feet of additional drilling.

Density testing and geotechnical logging of drill core are underway, samples have been selected for check assays at umpire labs, and additional multielement testing and geologic model updates are all ongoing. Bunker Hill’s engineering staff is currently evaluating potential options for incorporating the Cate-8 Target in short-term mine plans and evaluating the potential impact on future mine production profiles.

Should the program continue to demonstrate sufficient continuity, scale and confidence sufficient for the calculation of a future Measured and Indicated mineral resource, the Company anticipates incorporating this additional mineral inventory into its production planning process and full-year operational guidance for 2027.

JOIN BUNKER HILL MINING FOR A LIVE EXPLORATION UPDATE

Thursday, July 16 | 9:00 a.m. PT | 12:00 p.m. ET

Bunker Hill Mining invites shareholders, analysts, and prospective investors to join a live webinar highlighting the Company’s exploration strategy and recent drill results at the historic Bunker Hill Mine in Idaho’s prolific Coeur d’Alene Mining District.

President & CEO Sam Ash will be joined by Chief Geologist Sam Bourque to discuss:

• Highlights from the Company’s latest exploration program and drill results
• High-priority silver targets and geological potential across the Bunker Hill Mine
• Progress toward an initial mineral resource estimate
• How exploration supports future mine planning, production growth, and long-term shareholder value
• Live questions and answers with management

Register today to reserve your spot.
https://us06web.zoom.us/meeting/register/anUMpVE0QN-KgZaE3z7leQ

We look forward to sharing how Bunker Hill’s exploration program is advancing the Company’s long-term growth strategy.

INVESTOR TOUR – JULY 22, 2026

Interested participants are encouraged to RSVP by emailing [email protected]. Additional event details, including logistics and itinerary information, will be shared with registered attendees closer to the event date.

“We are excited to welcome investors and stakeholders to the Bunker Hill Mine for the first time since restarting operations,” added Mr. Ash. “Investor Day will provide an opportunity to showcase the substantial progress made on site and discuss the exciting path forward for Bunker Hill.”

QUALITY ASSURANCE / QUALITY CONTROL (“QA/QC”) 

The Company has implemented rigorous QA/QC protocols, including the insertion of blanks and standards in all sample batches. QA samples inserted into the assay batches for holes reported here all passed analyses of blanks and certified reference standards. Core sample intervals were selected based on visual geology and mineralization, and were cut, bagged and delivered to the lab by Bunker Hill geologists. Samples were split and cut on a core saw where necessary, following a cut line placed by the geologist dividing visible mineralization into equal proportions. In areas of poor drill recovery, sampling was conducted from run block to run block to avoid any spatial bias within the interval.

Samples were prepared and analyzed at SVL Lab located in Smelterville, Idaho, using standard industry grind, split, and pulp preparation, followed by microwave digestion and Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) analysis, with overlimit samples assayed by fire assay with a gravimetric finish for silver. SVL Analytical, Inc. is a full-service environmental and geochemical laboratory and holds ISO/IEC 17025 accreditation for Fire Assay and Geochemistry. SVL’s QA program meets the quality requirements set forth in the ISO/IEC 17025:2017 Standard, as evidenced by the inclusion and reporting of internal quality control samples with all results.

QUALIFIED PERSON 

Sam Bourque (AIPG CPG #11775), Chief Geologist of Bunker Hill, is the Company’s designated Qualified Person for this news release within the meaning of NI 43-101. Mr. Bourque has reviewed and approved the technical information contained herein. 

ABOUT BUNKER HILL MINING

Bunker Hill Mining Corp. is a U.S.-based mining company focused on the restart and operation of its flagship asset, the historic Bunker Hill Mine in northern Idaho’s prolific Silver Valley. One of North America’s most storied mining districts, the Bunker Hill Mine is being redeveloped as a modern producer of zinc, lead and silver concentrates through responsible mining practices and a disciplined approach to operational execution.

The Company’s strategy is centered on creating long-term value through the efficient restart, optimization and expansion of this high-quality asset while maintaining strong environmental stewardship, safety performance and community engagement. Bunker Hill is committed to delivering sustainable growth and maximizing shareholder returns by successfully redeveloping a cornerstone mining operation in the United States.

Additional information is available at www.bunkerhillmining.com and on SEDAR+ and EDGAR.

On behalf of Bunker Hill Mining Corp.
Sam Ash
President and Chief Executive Officer

For additional information, please contact:
Brenda Dayton
Vice President, Investor Relations
T: 604.417.7952
E: [email protected]

Cautionary Note Regarding Forward-Looking Statements

Certain statements in this news release are forward-looking and involve a number of risks and uncertainties. Such forward-looking statements are within the meaning of that term in Section 27A of the U.S. Securities Act of 1933, as amended, and Section 21E of the U.S. Securities Exchange Act of 1934, as amended, as well as within the meaning of the phrase “forward-looking information” in the Canadian Securities Administrators’ National Instrument 51-102 – Continuous Disclosure Obligations (collectively, “forward-looking statements”). Forward-looking statements are not comprised of historical facts. Forward-looking statements include estimates and statements that describe the Company’s future plans, objectives or goals, including words to the effect that the Company or management expects a stated condition or result to occur. Forward-looking statements may be identified by such terms as “believes”, “anticipates”, “expects”, “estimates”, “may”, “could”, “would”, “will”, “plan” or variations of such words and phrases.

Forward-looking statements in this news release include, but are not limited to, statements regarding: additional zones of mineralization; the preparation and completion of an initial resource estimate, with the aim of including in the production plan; the Cate-8 Target and Cate-8 Target Model; future drill, exploration and testing programs; geological interpretations and resource calculations; incorporation of the Cate-8 Target into short-term mine plans; Operational Investor Day and webinar and the Company’s general objectives, goals or future plans, and any similar statements. Forward-looking statements reflect material expectations and assumptions, including, without limitation, expectations and assumptions relating to: receive sufficient project financing for the ramp up of commercial production of the Bunker Hill Mine on acceptable terms or at all; the future price of metals; and the stability of the financial and capital markets. Factors that could cause actual results to differ materially from such forward-looking statements include, but are not limited to, those risks and uncertainties identified in public filings made by Bunker Hill with the U.S. Securities and Exchange Commission (the “SEC”) and with applicable Canadian securities regulatory authorities, including its latest annual report on Form 10-K as filed with the SEC on March 6, 2026, and the following: the Company’s inability to raise additional capital for project activities, including through equity financings, concentrate offtake financings or otherwise; capital market conditions; restrictions on labor and its effects on international travel and supply chains; failure to identify mineral resources; failure to convert estimated mineral resources to reserves; the preliminary nature of metallurgical test results; the Company’s ability to ramp up the Bunker Hill Mine to commercial production and the risks of not basing a production decision on a feasibility study of mineral reserves demonstrating economic and technical viability; delays in obtaining or failures to obtain required governmental, environmental or other project approvals; political risks; changes in equity markets; uncertainties relating to the availability and costs of financing needed in the future; inflation; changes in exchange rates; fluctuations in commodity prices; delays in the development of projects; and capital, operating and reclamation costs varying significantly from estimates and the other risks involved in the mineral exploration and development industry. Although the Company believes that the assumptions and factors used in preparing the forward-looking statements in this news release are reasonable, undue reliance should not be placed on such statements or information, which only applies as of the date of this news release, and no assurance can be given that such events will occur in the disclosed time frames or at all. The Company disclaims any intention or obligation to update or revise any forward-looking information, whether as a result of new information, future events or otherwise, other than as required by law. No stock exchange, securities commission or other regulatory authority has approved or disapproved the information contained herein.

Readers are cautioned that the foregoing risks and uncertainties are not exhaustive. Additional information on these and other risk factors that could affect the Company’s operations or financial results are included in the Company’s annual report and may be accessed through the SEDAR+ website (www.sedarplus.ca) or through EDGAR on the SEC website (www.sec.gov).

Photos accompanying this announcement are available at:

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