Bonterra Congratulates Gold Fields and Cree Partners on Landmark Impact Benefit Agreement for The Windfall Project

Val-d'Or, Quebec--(Newsfile Corp. - June 3, 2026) - Bonterra Resources Inc. (TSXV: BTR) (OTCQX: BONXF) (FSE: 9BR2) ("Bonterra" or the "Company") congratulates Windfall Mining Group Inc. ("Windfall Mining"), a wholly owned subsidiary of Gold Fields Limited ("Gold Fields"), together with the Cree First Nation of Waswanipi, the Cree Nation Government and the Grand Council of the Crees (Eeyou Istchee), on the signing of a landmark Impact Benefit Agreement for the Windfall Project, known as the Uukiimau Agreement.

Bonterra is partnered with Gold Fields on the Phoenix JV, which is adjacent to the Windfall Project, under a definitive earn-in and joint venture agreement (the "JV Agreement") with Windfall Mining (see press release dated November 28, 2023). The signing of the Uukiimau Agreement represents an important milestone for the broader Urban-Barry camp and reflects the continued advancement of responsible resource development in partnership with Indigenous communities.

Cesar Gonzalez, Executive Chairman & Interim CEO of Bonterra, commented: "On behalf of Bonterra, I would like to congratulate Gold Fields, Windfall Mining, the Cree First Nation of Waswanipi, the Cree Nation Government and the Grand Council of the Crees on this important achievement. The Uukiimau Agreement is a meaningful milestone for the Windfall Project and the region, and reflects the importance of building long-term partnerships based on respect, dialogue and shared benefits. As partners with Gold Fields on the Phoenix JV, we are encouraged by this important progress in the Urban-Barry camp."

Bonterra looks forward to the continued advancement of the Phoenix JV under the leadership of Gold Fields and in alignment with the highest standards of environmental stewardship, community engagement and responsible mineral development.

ABOUT BONTERRA

Bonterra is a Canadian gold exploration company with a portfolio of advanced exploration assets anchored by a central milling facility in Québec, Canada. The Company's assets include the Gladiator, Barry⁽¹⁾, Moroy, and Bachelor⁽²⁾ gold deposits, which collectively hold 16.8 million tonnes ("Mt") at an average grade of 3.02 g/t Au for 1.63 million ounces ("Moz") of Measured & Indicated Mineral Resources, plus 15.6 Mt at an average grade of 4.32 g/t Au for 2.17 Moz Au of Inferred Mineral Resources.

In November 2023, the Company entered into an earn-in and joint venture agreement with Osisko Mining Inc. ("Osisko Mining") for the Urban-Barry properties (the "JV Agreement"), which include the Gladiator and Barry deposits. In October 2024, Gold Fields, through a wholly owned Canadian subsidiary, completed the acquisition of Osisko Mining for C$2.16 billion. Gold Fields is now the counterparty to the JV Agreement and can continue to earn a 70% interest in the joint venture by incurring C$30 million in work expenditures on or before November 2026 (including expenditures incurred by Osisko Mining prior to October 2024). This strategic transaction highlights Bonterra's dedication to advancing its exploration assets, marking a significant step towards development.

(1) See news release of the Company dated February 23, 2026 and titled "Bonterra Reports Significant Mineral Resources Growth at Barry and Gladiator Deposits" for further details.
(2) See news release of the Company dated April 1, 2026 and titled "Bonterra Reports Significant Mineral Resource Growth at Bachelor and Moroy, 100% owned Deposits and Provides Corporate Updates" for further details. Marc-André Pelletier, P. Eng., President and CEO of the Company, and a qualified person within the meaning of National Instrument 43-101 - Standards of Disclosure for Mineral Projects, reviewed and approved the scientific and technical information contained in this news release.

Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

Caution regarding forward-looking statements

This news release contains forward-looking statements within the meaning of applicable securities laws. All statements other than statements of historical fact may be forward-looking and are often identified by words such as "may", "will", "plan", "expect", "anticipate", "estimate", and "intend". Forward-looking statements in this news release include, without limitation, statements regarding the continued advancement of the Phoenix JV, the potential significance of the Uukiimau Agreement for the broader Urban-Barry camp, and expectations regarding responsible resource development, environmental stewardship, community engagement and Indigenous partnerships in the region.

These statements are based on assumptions considered reasonable by management, including assumptions regarding exploration plans, budgets, schedules, regulatory approvals, and the continued advancement of work by Gold Fields. However, forward-looking statements involve known and unknown risks, uncertainties, and other factors that may cause actual results to differ materially. Such risks include, but are not limited to, changes to exploration plans, results that differ from expectations, operational or permitting challenges, the ability of the parties to complete the Joint Venture, the timing and completion of earn-in expenditures, the speculative nature of mineral exploration, commodity price fluctuations, and the availability of financing. Additional information regarding risks can be found in the Company's filings at www.sedarplus.ca.

Readers are cautioned not to place undue reliance on forward-looking statements. The Company does not undertake to update any forward-looking statement except as required by applicable securities laws. All forward-looking statements in this release are expressly qualified by this cautionary statement.

To view the source version of this press release, please visit https://www.newsfilecorp.com/release/299982