Whistlejacket update

Bradda Head Samples up to 3.03% Li2O and Expands Lithium Potential at Bradda's Whistlejacket Spodumene Lithium Project in Arizona USA

Bradda Head Lithium Ltd (AIM: BHLL), the North America-focused lithium development group, is pleased to announce that, following the recent approval of the Exploration and Drilling Permit (see announcement dated 26 May 2026), new surface sampling assay results at the Whistlejacket Lithium Project demonstrates strong lithium prospectivity across multiple target areas.

Additionally, Bradda Head Lithium and Rio Tinto subsidiary Kennecott Exploration Company ("KEX"), have also completed their first technical meeting and formally established the Technical Committee for the Whistlejacket project in Arizona. The meeting included a review of the current exploration programs, technical priorities, and upcoming drill targets identified across the project area.

Highlights:

• High values of 3.03 % Li2O, eighteen (18) samples exceeding 0.59 % Li2O out of 60 samples.
• Mostly coarse grained spodumene exhibits minimum surface alteration, an encouraging indication lithium mineralization that could be consistent with depth
• More field surface sampling planned
• Results from these additional samples will guide and refine drill hole targeting in this and future drilling campaigns
• Bradda Head and Rio Tinto subsidiary KEX have formally established a Technical Committee to oversee and direct exploration efforts on the Whistlejacket lithium project in Arizona.
• Strong ESG focus through engagement of local contractors, regional stakeholders, and responsible land stewardship practices.

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Ian Stalker, Executive Chair, commented:

"We are highly encouraged by the new assay results from the first stage of our surface sampling programme completed at Whistlejacket. The programme has refined and improved our exploration targeting and further reinforces the project's strong lithium potential.

The next set of results will further add to the knowledge base and hopefully add further new targets.

We have also achieved several important milestones supporting the advancement of our Arizona lithium exploration portfolio, including the formal establishment of a Technical Committee with Rio Tinto subsidiary KEX for the Whistlejacket Lithium Project. These developments position the Company to advance drilling across its spodumene-focused Arizona projects during 2026.

In parallel, Bradda Head continues to strengthen local stakeholder engagement, expand operational staffing, and advance ESG-focused initiatives as it builds a strategically important U.S. lithium portfolio aligned with the growing domestic critical minerals and battery supply chain sectors."

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Surface samples

The first batch of surface sample results has now been received from the project. The samples were collected from strategically selected pegmatites located within the northeastern portion of the claim block (Figure 1). A total of 62 samples were submitted to SGS for analytical testing (2 control samples and 60 rock samples), with 18 samples returning grades exceeding 0.59 % Li2O, including 12 samples grading above 1.00 % Li2O and values reaching up to 3.03 % LiO2. The results confirm widespread lithium mineralization associated with spodumene-bearing pegmatites exposed at surface. All 60 samples contain low iron, less than 1.0% and most below 0.5%, in addition to scattered anomalies in Ta, Cs, Nb, and Rb, although a clear picture of associations from these critical minerals has yet to be established.

Results have also identified two highly prospective target areas (Figure 2), including a continuous pegmatite outcrop where seven consecutive samples returned elevated lithium values alongside well-developed spodumene crystals visible at surface. The target area was previously tested during RTX's second exploration drilling campaign; however, the main mineralized zone may not have been fully evaluated, as the nearest drill hole trace is located approximately 160 m below surface. Recent structural measurements collected in the area also suggest that the pegmatite outcrop may dip in the opposite direction to the historical drill hole orientation, further enhancing the potential for additional mineralization and highlighting a compelling drill-ready target for the upcoming exploration campaign.

The Company will continue the sampling campaign planned, consisting of approximately 290 chip samples to be collected as part of the continued expansion of exploration activities across the project. The program is designed to refine and improve both previously identified and newly generated drilling targets. In parallel, a channel sampling campaign is also being planned to further evaluate and define lithium mineralization across priority target areas, with execution expected following completion of the upcoming drill campaign.

Technical Committee

The Technical Committee, comprising two representatives from each party, has been formed to oversee and guide exploration activities across the project area. The Committee will review exploration concepts, technical results, budgets, expenditures, and tenure matters, while facilitating the exchange of technical expertise between the parties. The Committee will act in an advisory capacity, with Bradda Head retaining sole operational decision-making authority under the Agreement. Upcoming meeting dates and quarterly reporting milestones have now been established, while the first-year exploration budget has been reviewed and approved, subject to minor refinements.

As part of its ESG framework, Bradda continues to work closely with local communities to maximize regional economic participation through the engagement of local contractors and service providers. The project also benefits from existing access infrastructure, with several established roads requiring only minimal upgrades, while maintaining positive and ongoing communication with the current surface grazing lessee. In parallel, the Company has designed its exploration programs with a strong emphasis on responsible land stewardship, including minimizing surface disturbance and implementing water conservation measures during drilling operations.

Additionally, Bradda has engaged proactively with the local community of Bagdad, Arizona, including coordination with regional operator Freeport-McMoRan on matters relating to safety, emergency response, and fire prevention. As exploration activities advance, the Company intends to host local elected officials and community representatives for site visits aimed at increasing awareness of the strategic importance of domestically sourced critical minerals and the potential long-term economic benefits the projects could bring to the region.

QAQC

Rock chip samples were collected in the field under the supervision of Hugo Zuniga (Senior Project Manager). Sample location sites were labelled, rock chip samples were bagged, tied off, then transported to the core shed under lock and key. Samples were delivered by the Company to SGS Preparation Lab in Tempe Arizona; after preparation were shipped to SGS Laboratories in Burnaby, B.C., Canada where SGS prepped then analyzed all samples using sodium peroxide fusion combined ICP-AES and ICP-MS, method GE_ICM90A50. Certified standards were inserted into the rock chip sample stream and reviewed by the Hugo Zuniga. The Company Qualified Person (QP), Mr Joey Wilkins, consents to the inclusion of the technical information in this release and context in which it appears.

Figure 1.- Location of samples assays

Figure 2.- New samples (cyan buffer), RTX samples (white buffer).

Qualified Person (Bradda Head)

For further information please visit the Company's website: www.braddaheadltd.com.

About Bradda Head Lithium Ltd.

The San Domingo Project comprises 248 claims covering approximately 1850 acres, located primarily on BLM land, along with two Arizona State Land Department claims. To date, 108 drill holes totaling 13,089 m of core drilling have been completed across three drilling campaigns. The project area hosts more than 1,000 mapped pegmatites, of which 18 have been identified as priority targets, with six tested by drilling. The area currently holds two active Notices of Intent (NOI) permits, and updated drilling plans are in place that can be implemented once all required permits for the pegmatite targets are secured. The objective of the next exploration phase is to further delineate the most prospective areas and advance them toward potential Mineral Resource Estimation (MRE) and NI 43-101 compliant reporting.

The Whistlejacket Project comprises nine Arizona State Land Department Mineral Exploration Permits (MEPs), covering a total of 2,010.7 hectares. The project is subject to a definitive Option to Joint Venture agreement with Kennecott Exploration Company (KEX) and targets spodumene-bearing pegmatites. KEX previous exploration includes 19 drilled diamond drill holes totaling 4,188 meters, with all holes intersecting lithium mineralization. Notable results include 51.0 meters at 1.11% Li₂O in hole WSTL0009 and 19.47 meters at 1.66% Li₂O in hole WSTL0008. In addition, the project has benefited from extensive surface mapping, sampling, airborne geophysics, and the acquisition of high-resolution aerial imagery, significantly enhancing the geological understanding and overall value of the asset.

Glossary