Mr. Marc-Andre Pelletier reports

BONTERRA PROVIDES EXPLORATION AND CORPORATE UPDATES

Bonterra Resources Inc. has provided exploration updates at its 100-per-cent-owned Desmaraisville South and at the Phoenix JV (joint venture) projects. Exploration work at Phoenix JV is being led by a 100-per-cent indirect subsidiary of Gold Fields Ltd. The project is under a definitive earn-in and joint venture agreement with Gold Fields. Under the JV agreement, Gold Fields has the right to acquire a 70-per-cent interest in the project by spending $30-million in work expenditures, with a minimum spending commitment of $10-million per year over a three-year period (see press release dated Nov. 28, 2023, for more details). To date, over 65,000 metres (m) have been drilled, with approximately $20-million invested in the project under the JV agreement.

Marc-Andre Pelletier, president and chief executive officer, commented: "The exploration program, led by our joint venture partner Gold Fields, is progressing well and has provided several valuable insights ahead of the 15,000 m drilling campaign, which is set to begin this week with a drill rig mobilized on the Duke NE target. Prospecting work conducted to date has allowed for the mapping and sampling of several areas, including outcrops, boulders and a historical trench located on the Gladiator SW target. In addition, a B-horizon soil sampling campaign was completed to the east and west of the Gladiator deposit, alongside an airborne gravimetric survey covering the entire JV property.

At the Desmaraisville South property, drilling is currently under way. Prospecting work is also scheduled to begin on the property this week. We are pleased with the progress achieved this year through the Phoenix JV and excited to advance both campaigns as drilling programs are now under way."

Exploration updates at Phoenix JV

The exploration program, which began in May, 2025, on the JV property, includes two gravimetric surveys -- one airborne and one ground-based -- as well as field activities such as B-horizon soil sampling, prospecting, mapping of outcrops and reviewing historical trenches.

The airborne gravimetric survey is now completed. The ground survey might resume once the airborne data has been compiled and analyzed. Prospecting activities to date have focused on the Gladiator SW outcrops, Titan target and areas near Lac-aux-Loutres. Mapping work will continue at Panache target. B-horizon soil samples were also collected at these targets.

The drilling campaign will start with one drill rig on the Duke NE target, and Gold Fields plans to deploy up to three drill rigs for a total of 15,000 m of drilling. Several targets will be tested including the Gladiator NE and Titan targets along the Barry shear zone.

Exploration updates at Desmaraisville South

At Desmaraisville South, the 2025 drill campaign started with one drill rig. To date, approximately 2,500 m have been drilled at Hewfran and Mistik targets. The company is planning a 10,000 to 12,000 m drill program expected to be completed by year-end and includes targets selected with the assistance of the Vrify's AI-assisted mineral discovery platform known as DORA. Field work is expected starting soon on the property.

Corporate updates

Following the closing of its upsized brokered private placement for proceeds of $10.5-million, announced on June 30, 2025, the company would like to clarify the number of non-transferable broker warrants issued in connection with this financing. The correct number of broker warrants issued is 2,509,109, not 2,509,108 as previously disclosed in the June 30, 2025, press release (see the June 30 press release for more information).

Qualified person

M. Donald Trudel, PGeo (OGQ No. 813), director geology for the company, has reviewed and approved the technical information contained in this press release. Mr. Trudel is a qualified person as defined by National Instrument 43-101 on standards of disclosure for mineral projects.

About Bonterra Resources Inc.

Bonterra is a Canadian gold exploration company with a portfolio of advanced exploration assets anchored by a central milling facility in Quebec, Canada. The company's assets include the Gladiator, Barry, Moroy and Bachelor gold deposits, which collectively hold 1.24 million ounces in measured and indicated categories and 1.78 million ounces in the inferred category.

In November, 2023, the company entered into an earn-in and joint venture agreement with Osisko Mining Inc. 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 $2.16-billion. Gold Fields is now the counterparty to the JV agreement and can continue to earn a 70-per-cent interest in the joint venture by incurring $30-million in work expenditures until 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 toward development.

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