Bonterra Intersects 34.7 g/t Au over 2.4 m at the Barry Underground Project and Provides an Update on the Duke Property Joint Venture Drill Program

2872 Sullivan Road, Suite 2 Val-d’Or, Quebec Office: (819) 825-8678

Bonterra Intersects 34.7 g/t Au over 2.4 m at the Barry Underground Project and Provides an Update on the Duke Property Joint Venture Drill Program

Val-d’Or, QC – March 27, 2023 – Bonterra Resources Inc. (TSX-V: BTR, OTCQX: BONXF, FSE: 9BR2) (“Bonterra” or the “Company”) is pleased to announce more results from the now completed infill drilling campaign at the Barry underground project, which holds 0.5 million ounces of Measured and Indicated Mineral resources and 0.7 million ounces of Inferred Mineral resources according to the last mineral resources estimate (the “2021 MRE”, see press release dated June 23, 2021). The primary goal of this campaign was to convert mineral resources to a higher confidence category and enhance the interpretation and grade continuity of the mineralization in the upper section of the deposit. In total, 31,349 meters (“m”) (91 holes) of infill drilling has been completed from surface since August 2022. The Company has received assays for 75 holes so far, including the ones in this release (see press releases dated November 15, 2022 and December 12, 2022 for previously released holes).

Highlights include:

• 34.7 g/t Au over 2.4 m, including 72.0 g/t Au over 1.1 m in hole MB-22-560A
• 17.7 g/t Au over 3.2 m, including 30.1 g/t Au over 1.8 m in hole MB-23-594
• 11.6 g/t Au over 3.3 m, including 19.8 g/t Au over 1.8m in hole MB-23-589
• 9.0 g/t Au over 9.2 m, including 21.7 g/t Au over 2.0 m in hole MB-22-578
• 8.2 g/t Au over 6.0 m, including 17.6 g/t Au over 2.7 m in hole MB-22-556
• 6.4 g/t Au over 4.0 m, including 13.2 g/t Au over 1.2 m in hole MB-22-565A

Duke Joint Venture Drill Program Update

In March, the Company announced a 3,300 m drill program at the Duke property (“Duke”), a joint venture with Osisko Mining Inc. (“Osisko”). As of now, six of ten holes have been drilled, and the drilling activities are tracking on schedule (see press release dated March 6, 2023). The drill results are expected to be released upon completion of the program.

The drill program at Duke is part of the Company's renewed focus on regional exploration at a rate of approximately 1,400 m per month in the Urban-Barry and Bachelor camps.

Marc André Pelletier, President and CEO commented: “The exploration program at Duke in collaboration with our joint venture partner Osisko is progressing well. Duke is located adjacent to the Company's Gladiator deposit and Osisko's Windfall gold project, as well as the Barry deposit to the west. Together, these three deposits contain a significant gold resource of over 10 million ounces, and the Company remains focused on exploring the Urban-Barry camp this year. Following the completion of the infill drill program at the Barry underground project, the Company plans to update the geological model of the underground deposit to determine the next steps for the Barry deposit. Additionally, an exploration program will soon take place at the Barry Northeast and Panache properties to test high potential exploration targets.”

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Diamond Drilling Results Highlights:

Figure 1 – Barry Project –Surface Plan, Holes, and Highlights Location

The completed infill drill program of the Barry underground project was designed to convert the Inferred resources from the 2021 MRE into Indicated resources by decreasing the drill spacing to 25 m. The program especially aims to delineate and expand high-grade mineralized shoots identified in the 2021 MRE. Results from recent assays, including those in this press release, underscore the potential of increasing quantity and continuity of the underground mineralization.

Figure 2 – Barry Project – Composite Long Section of the Barry Deposit Looking Northwest

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Infill drilling in the 800 zone continue to delineate and increase the length and continuity of the high-grade shoots. Results like 34.7 g/t Au over 2.4m including 72.0 g/t Au over 1.1 m in hole MB-22-560A, 16.3 g/t Au over 2.8 m including 26.6 g/t Au over 1.7 m in hole MB-22-585 and 17.7 g/t Au over 3.2 m including 30.1 g/t Au over 1.8 m in hole MB-23-594 enhance the potential of high grade continuous mineralized shoots in the 800 zone (Figure 3). Assays from 17 holes drilled in the zone 800 during winter are pending.

Figure 3 – Barry Project – Long Section, Zone 800 Looking Northwest

Infill Drilling into the H6/D4 moderate south dipping self-intersecting zones helped to better constrain the high-grade mineralization highlighted by the 2021 MRE. Infill drilling continues to highlight the continuity of high-grade shoots through the mineralized shears. Results as 9.0 g/t Au over 9.2 m including 21.7 g/t Au over 2.0 m in hole MB-22-578, 5.6 g/t Au over 6.3 m including 10.7 g/t Au over 2.0 m in hole MB-22-575 and 4.6 g/t Au over 7.7 m including 9.2 g/t Au over 2.5 m and 11.5 g/t Au over 0.7 m in hole MB-22-554 enhance the 300 m long continuity of large high grade shoots in zone H6 (Figure 4).

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Figure 4 – Barry Project – Long Section, Zone H6 and D4 Looking Northwest

Infill drilling in poorly defined H18 zone following the high-grade shoots has successfully intercepted high mineralization were predicted. Drill results highlight the potential for a 300 m long mineralized shoot in the shear zone located 20 m beneath the H6 shear. Demonstration is made by results in hole MB-22-565A with 6.4 g/t Au over 4.0 m including 13.2 g/t Au over 1.2 m, hole MB-22-564 returning 3.0 g/t Au over 10.4 m including 13.4 g/t Au over 1.1 m hole MB-22- 575 intercepting 4.7 g/t Au over 8.1 g/t Au including 11.6 g/t Au over 1.5 m and hole MB-22-578 with 10.7 g/t Au over 1.5 m.

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Figure 5 – Barry Project – Long Section, Zone H16 Looking Northwest

Barry Deposit Geology

The Barry gold deposit is characterized by three dominant sets of structures, all dipping to the southeast. The sub-vertical shear zones and the H-Series shear zones dipping 25 to 40 degrees are hosted within intermediate to mafic volcanics and tuffs with local felsic intrusions. Contact zones dip from 50 to 65 degrees along the lower and upper contacts of the D1, D2 and D3 felsic intrusions with mafic volcanics. Gold mineralization is associated with disseminated sulfides within shear zones and veins with local visible gold. The Barry deposit has been delineated over 1.4 kilometre along strike and 700 m below surface and remains open for expansion.

Diamond Drill Hole Results Table:

The following table shows the significant intersections of the drill holes presented in this press release.

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Notes:

1) The meterage represents the actual length of the drilled lengths.

2) Estimated true widths for the Barry interpreted zones are as follows: D series, AB series, H series 70% to 90% of core length, 800 series 50% to 70% of core length.

3) The mineralized intervals listed are above 0.5 g/t Au and with metal factor (grades x thickness) above 5.

4) Gold grades are uncut.

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Quality Control and Reporting Protocols

The Barry project’s drill core gold analyses are performed at Bachelor Mine Laboratory, Actlabs (Ste-Germaine-Boulé) and at AGAT Laboratories (Val d’Or). The Company’s laboratory and external laboratories employ a rigorous QA-QC analysis program that meets industry standards. The analyses are carried out by fire assay (A.A.) with atomic absorption finish at Bachelor Mine Laboratory and with gravimetric finish for assay above 10 g/t Au at Actlabs and AGAT laboratories. Blanks, duplicates, and certified reference standards are inserted into the sample stream to monitor the Laboratory’s performance. The Company's QA-QC program requires that at least 5% of samples be analyzed by an independent laboratory. These verification samples are sent to ALS Minerals laboratory facility located in Val-d'Or, Quebec. The verifications show a high degree of correlation with the Laboratory’s results.

Qualified Person

Donald Trudel, P.Geo., (OGQ # 813) Director of Geology of the Company oversees all exploration activities on the Barry property and has compiled and approved the 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 large portfolio of advanced exploration assets anchored by a central milling facility in Quebec, Canada. The Company has four main assets, Gladiator, Barry, Moroy, and Bachelor that collectively have a total of 1.24 million ounces in Measured and Indicated categories, and 1.78 million ounces in Inferred category. Importantly, the Company owns the only permitted and operational gold mill in the region. Bonterra is focused on graduating from advanced exploration to a development company to deliver shareholder value.

FOR ADDITIONAL INFORMATION

Marc-André Pelletier, President & CEO [email protected]

2872 Sullivan Road, Suite 2, Val d’Or, Quebec J9P 0B9 819-279-9304 | Website: www.btrgold.com

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.

Cautionary and Forward-Looking Statements

Caution regarding forward-looking statements

This press release contains “forward-looking information” that is based on Bonterra’s current expectations, estimates, forecasts, and projections. This forward-looking information includes, among other things, statements with respect to Bonterra’s exploration and development plans and placing the Bachelor-Moroy deposit under long-term care and maintenance. The words “will”, “anticipated”, “plans” or other similar words and phrases are intended to identify forward-looking information. This forward-looking information includes namely information with respect to the planned exploration programs and the potential growth in mineral resources. Exploration results that include drill results on wide spacings may not be indicative of the occurrence of a mineral deposit and such results do not provide assurance that further work will establish sufficient grade, continuity, metallurgical characteristics and economic potential to be classed as a category of mineral resource. The potential quantities and grades of drilling targets are conceptual in nature and, there has been insufficient exploration to define a mineral resource, and it is uncertain if further exploration will result in the targets being delineated as mineral resources. Forward-looking information is

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subject to known and unknown risks, uncertainties and other factors that may cause Bonterra’s actual results, level of activity, performance or achievements to be materially different from those expressed or implied by such forwardlooking information. Such factors include but are not limited to: uncertainties related exploration and development; the ability to raise sufficient capital to fund exploration and development; changes in economic conditions or financial markets, environmental and other judicial, regulatory, political and competitive developments; technological or operational difficulties or inability to obtain permits encountered in connection with exploration activities; and labour relations matters. This list is not exhaustive of the factors that may affect our forward-looking information. These and other factors should be considered carefully, and readers should not place undue reliance on such forward-looking information.