Mr. Sean Roosen reports

OSISKO DEVELOPMENT REPORTS FOURTH QUARTER AND YEAR-END 2023 RESULTS

Osisko Development Corp. has released its financial and operating results for the three and 12 months ended Dec. 31, 2023 (Q4 2023).

Q4 2023 highlights

Operating, financial and corporate updates:

• A total of 2,090 ounces of gold sold by the company from operating activities in the fourth quarter (10,743 ounces of gold sold in 2023), comprising:
  • 1,622 ounces of gold sold from the Trixie test mine located within the company's wider Tintic project (4,959 ounces of gold sold in 2023);
  • 468 ounces of gold sold from the Cariboo gold project by processing stockpiles at a third party processing facility (3,272 ounces of gold sold in 2023);
  • Nil ounces of gold sold from the San Antonio gold project (2,512 ounces of gold sold in 2023).
• A total of $6.9-million in revenues ($31.6-million in 2023) and $6.4-million in cost of sales ($32.3-million in 2023) generated from operating activities in the fourth quarter.
• On Oct. 10, 2023, the company announced that it received an environmental assessment (EA certificate for the company's 100-per-cent-owned Cariboo gold project. The EA certificate was granted by the Environmental Assessment Office of the Province of British Columbia (EAO) and supported by approval decisions from Hon. George Heyman, Minister of Environment and Climate Change Strategy, and Hon. Josie Osbourne, Minister of Energy, Mines and Low Carbon Innovation. The EA process was completed in consultation with and support of the first nations partners.
• On Nov. 15, 2023, the company and O3 Mining Inc. announced the successful formation and capitalization of Electric Elements Mining Corp. (EEM) to explore for lithium potential on certain James Bay properties in Eeyou Istchee Area, Nunavik, Que., transferred to EEM by the company and O3 Mining (the spinout transaction). Subsequently, EEM completed an equity financing for aggregate gross proceeds to EEM of approximately $4.1-million to finance the first phase of exploration and for general corporate purposes. After giving effect to the financing, Osisko Development and O3 Mining hold approximately 47 per cent and 12 per cent, respectively, of the outstanding EEM shares.
• On Dec. 28, 2023, the company announced that Luc Lessard, chief operating officer (COO), would retire from the company at the end of 2023 to pursue other personal and professional commitments. Eric Tremblay, a director on the board of directors and chair of the environmental, health and sustainability committee, has taken on the position of interim COO. Additionally, in December, 2023, Chris Pharness, vice-president, sustainable development, departed the company.
• As at Dec. 31, 2023, the company had approximately $43.5-million in cash.

Tintic project -- Utah, United States (100 per cent owned)

• 2023 Trixie exploration program. During Q4 2023, the company continued underground exploration and delineation activities on the existing Trixie deposit as part of its 2023 underground infill and exploration program.
  • In 2023, a total of 6,028 metres (m) (19,776 feet (ft)) were drilled in 73 underground diamond drill holes, including an additional one geotechnical hole totalling 349 m (1,145 ft), with assay results for 17 and eight diamond drilling holes released on Oct. 11, 2023, and Dec. 21, 2023, respectively. Assay results for all remaining drill holes from the 2023 exploration program were released on Feb. 22, 2024 (see subsequent to Q4 2023).
• Porphyry target drilling. An initial regional surface diamond drilling campaign to test for copper-gold-molybdenum porphyry mineralization potential, namely in the Big Hill area, commenced in early December, 2023, following receipt of the required surface drill permits. An initial 3,000 metres (9,842 feet) of two drilling holes comprises phase one of the surface diamond drilling program.
  • One diamond drill rig is currently active at surface testing a porphyry target at Big Hill and is at a current depth of 378 m (1,240 ft). The company completed a first drill hole at Big Hill to a depth of 1,180 m (3,872 ft) when it transitioned out of the prospective alteration zone, and commenced the second drill hole by repositioning the drill rig at a modified angle.
  • One diamond drill hole tested a copper-gold-porphyry target below Trixie from underground and was drilled to a depth of 759.6 m (2,492 ft) when it crossed the Eureka Lily fault to the east and out of the prospective alteration zone. Further drill testing of a copper-gold porphyry target at depth below the Trixie deposit is recommended to the west.
  • The drilling of porphyry targets continues and is expected to be completed by the end of Q2 2024, at which point the company will provide an exploration update including any material assay results relating to the preliminary drilling program, as appropriate.
• Exploration target potential. The company has advanced rehabilitation at the 750 level to allow for further underground diamond drilling to test for the down dip extent of the 756 zone and the porphyry target below Trixie. Data compilation from historic mines in the area is continuing and is anticipated to generate additional exploration drill targets on the greater Tintic project property.
  • Test mining activities at Trixie were suspended in December, 2023, and are expected to remain in care and maintenance for the foreseeable future pending completion of technical work and additional funding.
• 2024 Trixie mineral resource estimate (MRE). Subsequent to Q4 2023, on March 15, 2024, the company released an updated MRE for the underground Trixie deposit in accordance with NI 43-101 (as defined herein). The 2024 Trixie MRE incorporated an additional 1,674 underground chip samples over 1,678 m (5,507 ft) of underground development, and 7,385 m of drilling (24,229 ft) in 122 holes completed since the initial Trixie MRE, with an effective date of Jan. 10, 2023. The 2024 Trixie MRE, which will be further described in the full technical report being prepared for the 2024 Trixie MRE in accordance with National Instrument 43-101, comprises:
  • Measured resources of 119,847 tonnes grading 27.36 grams per tonne (g/t) gold (Au) and 61.73 g/t silver (Ag), for a total of 105,437 ounces (oz) Au and 237,868 oz Ag.
  • Indicated resources of 124,743 tonnes grading 11.17 g/t Au and 59.89 g/t Ag, for a total of 44,811 oz Au and 240,211 oz Ag.
  • Inferred resources of 201,603 tonnes grading 7.80 g/t Au and 48.55 g/t Ag, for a total of 50,569 oz Au and 314,678 oz Ag.
• Trixie non-cash impairment. The company completed a review of the carrying value of its assets in accordance with international financial reporting standards as at Dec. 31, 2023. As a result of this review, a non-cash impairment gross charge of $160.5-million ($115.9-million on a net carrying value basis) was recognized for Trixie in the company's consolidated financial statements for the year ended Dec. 31, 2023.
  • As previously disclosed, the impairment charge is primarily a result of, among other things, assumptions related to required future exploration and capital expenditures, potential mining and processing methods, and average processed gold grades related to the gold targets only.
  • The asset impairment charge relates only to Trixie and is a non-cash item and, for the avoidance of doubt, has no impact on company's cash flows.

Cariboo gold project -- British Columbia, Canada (100 per cent owned)

• Permitting progress. Receipt of the EA certificate in October, 2023, successfully concludes the EA process for the Cariboo gold project, which was launched in October, 2019. A joint permit application for the B.C. Mines Act/Environmental Management Act is in progress, and the company is currently advancing through round three of the mine review committee review period. The company anticipates receiving permits in Q2 2024 which would enable construction of the Cariboo gold project. The company continues to explore its options, including sourcing a fully financed solution for the Cariboo gold project.
• Preconstruction activities. Subsequent to Q4 2023, the company secured a $50-million (U.S.) credit facility (as defined herein), which will be exclusively used to finance continuing detailed engineering and preconstruction activities at the Cariboo gold project. This includes the commencement of an underground development drift from the existing Cow Portal into the Cariboo gold project's mineral deposit at Lowhee zone and extraction of 10,000 tonnes of material under an existing provincial permit expected to be completed by the end of Q4 2024.

San Antonio gold project -- Sonora State, Mexico (100 per cent owned)

• Following completion of processing of the remaining stockpile inventory from the heap leach pad in Q3 2023, the San Antonio gold project was placed into care and maintenance, with no production anticipated henceforth.
• The company awaits next steps from the government of Mexico with respect to the permitting process and the status of open pit mining in the country.
• Strategic review. The board of directors of the company has authorized a strategic review of the San Antonio gold project, which includes exploring the potential for a financial or strategic partner in the asset or for a full or partial sale of the asset. The company has engaged a financial adviser in connection with such strategic review.

Subsequent to Q4 2023

• On Feb. 2, 2024, the company announced that Francois Vezina resigned from his position as senior vice-president, project development, technical services and environment effective as of March 1, 2024, to pursue outside interests in the mining sector.
• On Feb. 22, 2024, the company disclosed the remaining assay results from 14 diamond drilling holes and chip samples from new development areas as part of its 2023 exploration program at Trixie. Select assay results highlights included (see news release dated Feb. 22, 2024):
  • 66.04 g/t Au and 167.64 g/t Ag over 8.99 m in hole TRXU-DD-23-072A (1.93 troy ounces per short ton (oz/t) Au and 4.89 oz/t Ag over 29.50 ft).
• On March 4, 2024, the company announced that the company, as guarantor, and Barkerville Gold Mines Ltd., its wholly owned subsidiary, as borrower, entered into a credit agreement dated March 1, 2024, with National Bank of Canada in connection with a $50-million (U.S.) delayed draw term loan. The credit facility will be exclusively used to finance continuing detailed engineering and preconstruction activities at the Cariboo gold project. On March 1, 2024, an amount of $25.0-million (U.S.) ($33.9-million) was drawn under the credit facility, net of $1.0-million (U.S.) ($1.4-million) of fees.

Consolidated financial statements

The company's audited consolidated financial statements and management's discussion and analysis (MD&A) for the three and 12 months ended Dec. 31, 2023, are available on the company's website, on SEDAR+ and on EDGAR under Osisko Development's issuer profile.

Qualified persons

The scientific and technical information contained in this news release has been reviewed and approved by Maggie Layman, PGeo, vice-president, exploration, of Osisko Development, a qualified person within the meaning of National Instrument 43-101 -- Standards of Disclosure for Mineral Projects.

Technical reports

Information relating to the Cariboo gold project and the Cariboo FS is supported by the technical report titled "Feasibility Study for the Cariboo Gold Project, District of Well, British Columbia, Canada," dated Jan. 10, 2023 (amended Jan. 12, 2023), with an effective date of Dec. 30, 2022, prepared for the company by independent representatives BBA Engineering Ltd. and supported by independent consulting firms, including InnovExplo Inc., SRK Consulting (Canada) Inc., Golder Associates Ltd. (amalgamated with WSP Canada Inc. on Jan. 1, 2023, to form WSP Canada Inc.), WSP USA Inc., Falkirk Environmental Consultants Ltd., Klohn Crippen Berger Ltd., KCC Geoconsulting Inc. and JDS Energy & Mining Inc. Reference should be made to the full text of the Cariboo technical report, which was prepared in accordance with NI 43-101 and is available electronically on SEDAR+ and on EDGAR under Osisko Development's issuer profile and on the company's website.

Certain scientific and technical information relating to the Tintic project and the updated mineral resource estimate for the Trixie deposit is supported by the news release disseminated by the company on March 15, 2024 (titled "Osisko Development Announces Mineral Resource Update for the Trixie Deposit, Tintic Project"). The key assumptions, parameters, qualifications, procedures and methods underlying the 2024 Trixie MRE, certain of which are described in the noted news release, will be further described in the full technical report being prepared for the 2024 Trixie MRE in accordance with NI 43-101, and will be available on SEDAR+ under the company's issuer profile within 45 days from the date of the MRE update news release. Information relating to the 2024 Trixie MRE provided herein is qualified in its entirety by the full text of the MRE update news release which is available electronically on the company's website or on SEDAR+ and on EDGAR under the company's issuer profile, including the assumptions, qualifications and limitations therein.

Until a technical report relating to the 2024 Trixie MRE is filed on SEDAR+, the current technical report (within the meaning of NI 43-101) on the Tintic project is the technical report titled "NI 43-101 Technical Report, Initial Mineral Resource Estimate for the Trixie Deposit, Tintic Project, Utah, United States of America," dated Jan. 27, 2023 (with an effective date of Jan. 10, 2023), which was prepared by William J. Lewis, PGeo, Ing, Alan J. San Martin, MAusIMM (CP), and Richard Gowans, PEng. The full text of the 2023 Trixie MRE is available electronically on the company's website or on SEDAR+ and on EDGAR under the company's issuer profile, including the assumptions, qualifications and limitations therein. Once a technical report in respect of the 2024 Trixie MRE is filed on SEDAR+ under the company's issuer profile, it will automatically supersede the Tintic technical report.

Information relating to San Antonio is supported by the technical report titled "NI 43-101 Technical Report for the 2022 Mineral Resource Estimate on the San Antonio Project, Sonora, Mexico," dated July 12, 2022 (with an effective date of June 24, 2022), prepared for the company by independent representatives of Micon International Ltd. Reference should be made to the full text of the San Antonio technical report, which was prepared in accordance with NI 43-101 and is available electronically on SEDAR+ and on EDGAR under Osisko Development's issuer profile and on the company's website.

About Osisko Development Corp.

Osisko Development is a North American gold development company focused on past-producing mining camps located in mining friendly jurisdictions with district-scale potential. The company's objective is to become an intermediate gold producer by advancing its 100-per-cent-owned Cariboo gold project, located in central British Columbia, Canada, the Tintic project in the historic East Tintic mining district in Utah, United States, and the San Antonio gold project in Sonora, Mexico. In addition to considerable brownfield exploration potential of these properties, that benefit from significant historical mining data, existing infrastructure and access to skilled labour, the company's project pipeline is complemented by other prospective exploration properties. The company's strategy is to develop attractive, long-life, socially and environmentally sustainable mining assets, while minimizing exposure to development risk and growing mineral resources.

We seek Safe Harbor.