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EXHIBIT INDEX

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Prepared by the following Qualified Persons: ▪ Colin Hardie, P.Eng. .........................BBA Engineering Ltd. ▪ Mathieu Bélisle, P.Eng. .....................BBA Engineering Ltd. ▪ Katherine Mueller, P.Eng. ................Falkirk Environmental Consultants Ltd. ▪ John Cunning, P.Eng. ......................Golder Associates Ltd. ▪ Paul Gauthier, P.Eng. .......................Golder Associates Ltd. ▪ Aytaç Göksu, P.Eng. ........................Golder Associates Ltd. ▪ Saileshkumar Singh, P.Eng...............Golder Associates Ltd. ▪ Eric Lecomte, P.Eng. ........................InnovExplo Inc. ▪ Vincent Nadeau - Benoit, P.Geo. ....InnovExplo Inc. ▪ Carl Pelletier, P.Geo.........................InnovExplo Inc. District of Wells, British Columbia, Canada Prepared for: Osisko Development Corp. Effective Date: December 30, 2022 Signature Date: January 10, 2023 ▪ Jean - François Maillé, P.Eng. .......... JDS Energy & Mining Inc. ▪ Keith Mountjoy, P.Geo.................... KCC Geoconsulting Inc. ▪ Michelle Liew, P.Eng........................ Klohn Crippen Berger Ltd. ▪ David Willms, P.Eng. ........................ Klohn Crippen Berger Ltd. ▪ Timothy Coleman, P.Eng. ............... SRK Consulting (Canada) Inc. ▪ Thomas Rutkowsky, P.Eng............... WSP USA Inc. ▪ Laurentius Verburg, P.Geo ............. WSP USA Inc.

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Date and Signature Page

This technical report is effective as of the 30^th day of December 2022.

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

TABLE OF CONTENTS

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

LIST OF TABLES

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

LIST OF FIGURES

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

List of Abbreviations

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

List of Abbreviations – Units of Measurement

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

This NI 43-101 Technical Report Feasibility Study (“FS”) for the Cariboo Gold Project (the “Project”) (the “Report”) was prepared and compiled by BBA Engineering Ltd. (“BBA”) at the request of Osisko Development Corp. (“ODV”). The Project is an advanced stage gold exploration project located in the historic Wells-Barkerville mining camp, in the District of Wells (“Wells”), British Columbia (“BC”), Canada. The purpose of this Report is to summarize the results of the FS for the Project in accordance with the guidelines of the Canadian Securities Administrators National Instrument 43-101 (“NI 43-101”) and Form 43101.

This Report was prepared based on contributions from several independent consulting firms including, BBA Engineering Ltd. (“BBA”), Falkirk Environmental Consultants Ltd. (“Falkirk”), Golder Associates Ltd. (amalgamated with WSP Canada Inc. on 1 January 2023 to form WSP Canada Inc.) (“Golder”), InnovExplo Inc.(“InnovExplo”), JDS Energy and Mining Inc. (“JDS”), KCC Geoconsulting Inc. (“KCC”), Klohn Crippen Berger Ltd. (“KCB”), SRK Consulting (Canada) Inc. (“SRK”), and WSP USA Inc. (“WSP”). This study provides a base case assessment for developing the Cariboo Gold deposit as an underground mine with a Services Building, including a concentrator located at the Mine Site Complex (“MSC”) at Wells and further processing at the Quesnel River (“QR”) Mill. The Project is designed in phases: in Phase 1, a 1,500 tonnes per day (“tpd”) crushing and ore sorting plant will be built at the Bonanza Ledge Site, located 3.5 kilometres (“km”) from the MSC in Wells, and in Phase 2, a pre-concentrator designed to have a capacity of 4,900 tpd will be built at the MSC. The QR Mill will ramp down from 859 tpd in Phase 1 to 644 tpd in Phase 2. The pre-concentration steps in Phase 2 are designed to produce less concentrate at higher grades. The MSC and the QR Mill are separated by approximately 111 kilometres (“km”). Waste rock storage will be located at the Bonanza Ledge Site, which will store 8.5 million tonnes (“Mt”) of waste material from the Project.

All monetary units in the Report are in Canadian dollars (“CAD” or “$”), unless otherwise specified. Costs are based on fourth quarter (Q4) 2022 dollars. Quantity and grades are rounded to reflect that the reported values represent approximations.

The major FS contributors and their respective areas of responsibility are presented in Table 1-1.

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Table 1-1: Report contributors

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

The reader is advised that the results of the FS summarized in this Report are intended to provide an initial, high-level review of the Project and potential design options. The FS mine plan and economic model include numerous assumptions. Only Measured and Indicated Resources (i.e. “Proven” and “Probable” Reserves) have been used in the economic analysis as defined by Canadian Securities Administrators' National Instrument 43-101 in FS studies.

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

The following list details the key project outcomes of the Report:

The Project is located in ODV’s Cariboo Gold Project Main Block, a group of claims located in the historical Wells-Barkerville mining camp of British Columbia that extends for approximately 77 km from northwest to southeast.

The Project falls within the Cariboo Regional District (“CRD”), a division of the local government system in BC, and Wells, BC. Wells is situated 74 km east of Quesnel, approximately 115 km southeast of Prince George, and approximately 500 km north of Vancouver.

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

ODV’s land holdings consist of 415 mineral titles totalling 155,088.69 hectares (“ha”) across two contiguous property blocks known as the Cariboo Main Block and the QR Mill site. These mineral titles include mineral claims, mineral leases, placer claims, and placer leases.

Through its 100% owned subsidiary Barkerville Gold Mines Ltd. (“BGM”), ODV holds 100% interest in 56 Cariboo Main Block placer titles, 35 QR Mill Property mineral claims, the QR mineral lease No. 320752, and 362 of the 379 Cariboo Main Block mineral and placer claims and placer leases. 17 mineral claims are jointly owned with other companies and individuals: ODV holds a 97.5% interest in six mineral claims, a 85% interest in two mineral claims, and a 50% interest in the other nine mineral claims.

The Project also contains 546 private land parcels from Crown-granted mineral claims (3,330.20 ha) that overlap many of the mineral titles where BGM is the registered owner on the title of the surface and/or undersurface rights to the parcels. A net smelter return (“NSR”) royalty of 5% payable to Osisko Gold Royalties Ltd. (“OGR”) is the only royalty that applies to the Project.

The Project lies within the Kootenay Terrane of the Omineca Tectonic Belt in the south-central Canadian Cordillera. The Omineca rocks were complexly deformed by Middle Jurassic to Early Tertiary compressional tectonics, and by Tertiary transtension and extension. The Kootenay Terrane in the vicinity of the Project is subdivided into the eastern Cariboo and western Barkerville subterranes. The Cariboo Subterrane is juxtaposed on the Barkerville Subterrane by the east-dipping Pleasant Valley Thrust.

The Snowshoe Group, central to the Barkerville Subterrane, hosts the Project.

The Barkerville and Cariboo Subterranes comprise metamorphosed equivalents of continent-derived siliciclastic protoliths with interlayered marble units and granitic orthogneiss. The subterranes are pericratonic in character and are thought to have formed near the current western margin of Laurentia. Various authors suggest that both Barkerville and Cariboo Subterranes share the same tectostratigraphic position and depositional environment.

The principal gold-producing areas in the Barkerville Subterrane are hosted in rocks metamorphosed to lower-greenschist facies (sub-biotite isograd); amphibolite-facies rocks are locally found on the Project but are not associated with any significant mineralization. The S1 and S2 fabrics are defined by phyllosilicate minerals (sericite and chlorite); they generally define foliation suggesting that peak metamorphic temperature coincided with the formation of cleavage.

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Lode-gold mineralization in the Wells-Barkerville mining camp (Cariboo Gold District) shares many characteristics with an orogenic gold deposit model. Gold mineralization is associated with orogenic silica-carbonate-sericite-pyrite stable fluids moving along secondary permeability controlled by metamorphic fabrics, vein arrays, faults, lithologic contacts, and rheological contrasts.

Deposit types on the Project consist of vein and replacement-type mineralization grouped into five inter-related styles: 1) Fault-fill breccia veins subparallel to foliation (S1), hosted in carbonaceous mudstone; 2) Vertical northeast-trending extensional (axial planar) veins dominantly hosted in sandstone units in S3 cleavages; 3) Fractured moderately dipping east-northeast-trending shear veins, hosted in sandstone units; 4) Gold bearing sulphide replacements hosted in fold hinges of calcareous sandstone units; and 5) Gold-bearing sulphide replacement mineralization hosted in fault-bounded calcareous siltstone units.

ODV’s exploration team executed a systematic methodology to the exploration program on the Project. The program included geological mapping, channel, soil, underground sampling, and diamond drilling.

The exploration team has continued its geological mapping across the Project’s area to identify lithologic contacts, define alterations and geochemical signatures, record micro- and macro-scale structural data, and to collect select rock samples. The targeted deposit types within the Project are structurally and/or geochemically controlled, thus the mapping data continues to play a vital role in refining the geologic model of the area and defining mineralized zones.

The objectives for the 2020 and 2021 diamond drilling programs (the “2020 Program” and the “2021 Program”) were to test new brownfields targets adjacent to known deposits, infill high-grade vein corridors modelled from the 2019 Preliminary Economic Assessment (“PEA”) classified as Inferred and explore the depth potential of known deposits.

The focus of the 2022 diamond drilling program (the “2022 Program”) was the infill of a proposed underground bulk-sampling area, the continued category conversion from Inferred to Indicated status of modelled vein corridors, and the delineation of additional vein corridors. The 2022 Program started on March 25, 2022, and was completed on July 06, 2022.

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

The 2022 Feasibility Mineral Resource Estimate for the Project (the “2022 FS MRE”) encompasses updated resources for the deposits of Cow Mountain (Cow Zone and Valley Zone), Island Mountain (Shaft Zone and Mosquito Zone), and Barkerville Mountain (Lowhee Zone and KL Zone). The updates were prepared by Daniel Downton, P.Geo., of Osisko Development (“ODV”), and reviewed and validated by Carl Pelletier, P.Geo., and Vincent Nadeau-Benoit, P.Geo., both of InnovExplo Inc. (“InnovExplo”), using all available information. Since the 2022 Preliminary Economic Assessment Mineral Resource Estimate (“MRE”), dated May 17, 2022 (the “2022 PEA MRE”), no new gold assay results were added to the databases for the Mosquito, Cow, and KL Zone deposits, but gold resources in a dilution halo and silver mineralization estimates in the vein corridors were added to the models. No changes are reported for the Bonanza Ledge or BC Vein (Barkerville Mountain) deposits. To report the 2022 FS MRE for the Project, conceptual “potential mining shapes” were used as constraints to demonstrate mineralized continuity and to show that the “reasonable prospects for eventual economic extraction” criteria is met, as defined in the Canadian Institute of Mining (“CIM”) Definition Standards on Mineral Resources and Reserves (CIM Definition Standards, 2014) and the CIM Estimation of Mineral Resources and Mineral Reserves Best Practice Guidelines (MRMR Best Practice Guidelines, 2019). The Mineral Resource updates for Shaft, Valley, and Lowhee Zones include new information from the end of the 2021 exploration program. The dilution halos and silver estimate additions contain data from all previous drilling campaigns, including previously validated historic information.

The 2022 FS MRE covers all the deposits in the Cow-Island-Barkerville Mountain Corridor. The resource area for the Cow Mountain/Island Mountain segment covers a strike length of 3.7 km and a width of approximately 700 metres (“m”), down to a vertical depth of 600 m below surface. The estimate for the Barkerville Mountain segment covers a strike length of 3 km and a width of approximately 700 m, down to a vertical depth of 500 m below surface.

Two diamond drill hole databases cover the Project: Bonanza Ledge and BM-CM-IM (Barkerville Mountain including the BC Vein, KL, and Lowhee deposits, Cow Mountain including the Cow and Valley deposits, and Island Mountain including the Shaft and Mosquito deposits). These databases were filtered by deposit (Cow, Shaft, Valley, Mosquito, BC Vein, KL, or Lowhee) before the work in Datamine. A subset of drill holes was used to generate the 2022 FS MRE database for each deposit, as follows:

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

The qualified persons (“QP”) data verification included the diamond drill hole databases (the “ODV Databases”) used for the 2022 FS MRE, as well as the review and validation of the geological models of each deposit, the review of information on mined-out areas, and the data for selected drill holes (assays, quality assurance/quality control [“QA/QC”] program, downhole surveys, lithologies, alteration and structures).

The QPs also reviewed and validated the resource estimation process followed by ODV, including all parameters, geological interpretation, basic statistics, variography, interpolation parameters, block model construction, scripts that run the model, volumetric report, and the validation process.

Historical work subject to verification consisted of the holes used for the 2022 Preliminary Economic Assessment MRE (“2022 PEA MRE”) (Hardie et al., 2022). Basic cross-check routines were performed between the current ODV Databases and the previously validated database for the 2022 PEA MRE.

The QPs were granted access to the assay certificates for all holes in the 2021 drilling programs. Assays were verified for 5% of the drill holes. No discrepancies were found.

Overall, the QPs data verification demonstrates that the data, protocols, and estimation process for the Project are acceptable. The QPs consider the ODV databases to be valid and of sufficient quality to be used for the Mineral Resource Estimate herein.

ODV updated, in 2022, the geological models for the Valley, Shaft, and Lowhee deposits using historical data, the data from the 2015–2019 drilling programs, and new holes from the 2020–2021 drilling programs. The KL and BC Vein deposit were not drilled in 2021 and the Mosquito and Cow deposits had no new data since the May 17, 2022 update, though the geological models were reviewed by the QPs. The Bonanza Ledge geological model, initially from Brousseau et al. (2017), was reviewed and validated by the QPs.

A total of 482 geological solids were created and/or updated for all the deposits.

The QPs have classified the 2022 FS MRE as Measured, Indicated, and Inferred Mineral Resources based on data density, search ellipse criteria, drill hole density, and interpolation parameters. The 2022 FS MRE is considered to be reliable and established on quality data and geological knowledge. The 2022 FS MRE follows the 2014 CIM Definition Standards on Mineral Resources and Reserves.

Table 1-2 displays the results from the 2022 FS MRE, exclusive of the reserves, for the Project for all eight deposits: Cow, Valley, Shaft, Mosquito, KL, Lowhee, BC Vein, and Bonanza Ledge.

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Table 1-2: Cariboo Gold Project 2022 FS MRE

Reported at a 2.0 g/t Au cut-off grade (except for Bonanza Ledge reported at a 3.5 g/t Au cut-off grade)

Mineral Resource Estimate notes:

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

The Project consists of three main zones (Cow, Shaft, and Valley) with two smaller satellite zones (Lowhee and Mosquito). The rate of exploitation of each deposit will change over time, while the overall steady state production rate is 4,900 tpd. In 2024, production will begin at 1,500 tpd (pending permitting) for 2.75 years and will ramp up to 4,900 tpd (pending permitting) in 2027 for 8.5 years.

The selected mining method is mainly long hole longitudinal retreat with some stopes using a modified long hole longitudinal retreat method. Primary materials handling fleet will comprise of 10 tonne (t) scooptram Load Haul Dump (“LHD”) and 50 t haul trucks.

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Pre-production of the underground workings is set to begin in 2023 with 1,500 tpd achieved in September 2024 and full production of 4,900 tpd at the MSC in Q4 2027. Underground mine life is set to last until January 2036.

A hydrogeological investigation program was completed to provide key groundwater related inputs to the FS, namely, to estimate potential mine dewatering rates, to understand further the regional groundwater flow regime, and to characterize potential impacts of mine dewatering on groundwater and surface water systems.

SRK undertook two geotechnical field investigation programs on the Project designed to characterize the rock geotechnical conditions and support the underground mine and infrastructure designs. These investigations also supported structural geology reviews, detailed evaluation of geotechnical design domains, and the development of geotechnical design guidelines within each of these domains. These guidelines included excavation design parameters, estimates of dilution, as well as support requirements.

The 2018 geotechnical field data acquisition program included drilling and logging of 13 dedicated geotechnical drill holes. The 2021 geotechnical field data acquisition program included drilling and logging of five dedicated geotechnical drill holes. During both programs, representative rock core samples from each geotechnical domain were collected from the geotechnical drill holes for laboratory testing.

A review of photographs taken of exploration drill holes was undertaken from 2020 to 2022 to build a broader geotechnical understanding of the rock mass conditions across the Project site to optimize the geotechnical design. A total of 83,047 m of photo-logging has been conducted to date.

In addition to the 3D structural model created by ODV to represent the major Regional Fault structures on the Cariboo Gold Project property, SRK also provided a 3D fault model that was created for the secondary structures.

The geotechnical evaluation focused on a qualitative drill-hole-based assessment of the rock mass forming the immediate hanging wall and footwall of the proposed mineable stopes in each vein. Planned stopes in each major vein corridor, in each mining zone were individually assessed based on the lithology logging data provided by ODV, the regional structural model provided by ODV, the secondary structural model provided by SRK, the current understanding of existing historic mine workings, the geotechnical data acquired from the field program, and qualitative photographic review of drill holes intercepting the planned stopes.

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Excavation stability assessments have been completed using well-established empirical and semi-empirical relationships and engineering experience. The design procedure involves two steps: the quality of the rock mass is rated using a pre-defined classification system, and then the expected performance of the underground openings is predicted using an empirically derived stability correlation with the rock mass quality.

Sub-level open stoping with a sub-level spacing of 30 m is achievable in rock mass Class 1 to Class 3 lower by varying the open strike length and the use of two-phase backfill in the Class 3 lower rock mass in the Shaft Zone where stope widths are less than 5 m.

Mining Method Description

The long hole mining method was primarily selected due to the sub vertical geometry of mineralized vein corridors and the relatively lower cost. This method involves driving two drifts longitudinally along the mineralized vein corridors to define a stope. The top access serves as a drilling platform while the bottom access allows for mucking of drilled then blasted material. Once empty, these stopes are then backfilled with either paste fill or cemented rockfill. Stopes are mined retreating towards the access. This method allows for simultaneous mining of stopes along different vein corridors as well as along the same corridor if a pillar exists between active levels. A modified longitudinal method will also be used to a lesser extent (10% of the tonnage). That method essentially follows the same approach as the first one, except that the mucking and backfilling are done in two steps to limit the size of the exposed walls. This method will only be used for stopes located in poor ground during Phase 2, since paste backfill is required.

The minimum designed stope width for all zones is 3.7 m and the sill to sill stope height for all zones is 30 m. The maximum permissible strike length (the distance along strike that can be mined before backfilling is required) is a function of geotechnical constraints and differs by zone.

There will be two portals accessing underground ramps. The Cow Portal will allow access to the Lowhee, Shaft, and Mosquito zones in the earlier stages of the Project. The Valley portal will be built during the expansion to develop the Main ramp connecting the previous zones to the new Cow and Valley Zones. The Valley Portal will be used as the main services access. The zones are accessed by main ramps connecting to haulage drifts, and each individual zone has an internal ramp system. The Mosquito Zone is further west, connected to Shaft Zone by a 1,150 m long haulage drift.

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Each zone is planned to be mined with the longitudinal retreat long hole method, except for the Shaft Zone and Mosquito Zone that will be mined using both mining methods. Sublevels for all zones are 30 m sill to sill and a combination of Cemented Rock Fill (“CRF”) and paste fill are planned to backfill mined stopes. Stope strike lengths vary by zone based on geotechnical assessments of each zone. All zones are capped by a crown pillar (15 m for Cow and Valley and 20 m for Shaft and Mosquito) and vary in depth.

A major piece of underground infrastructure for the Phase 2 of the Project is the underground crushing system. This crusher is located below the services building in a location that has been identified as geotechnically favourable for long-term infrastructure. Ore will be brought to the crusher by underground trucks from all mining zones.

Ore will ultimately be brought to surface using a vertical conveyor to be pre-concentrated by sorting and flotation. The material rejected by the sorter will be transferred back underground using a wastepass raise and then it will either be used as backfill material or hauled to the Bonanza Ledge Waste Rock Storage Facility (“WRSF”) using automated trucks.

The mine will include haulage drifts connecting the five separate zones, an underground garage, and pumping stations. The Valley Portal will provide access for material and the labour force.

The development schedule has been created with a combination of traditional jumbo development and roadheaders. The roadheaders are scheduled to provide a lateral advance of 200 m per month in single heading conditions and will be concentrated on the ramps and level access development. The jumbos will provide an average overall lateral advance of 300 m per month per jumbo crew when multiple active headings are available. Lateral development will rely on contractors for the initial pre-production phase, with a handover to mine personnel with the initiation of production.

During Phase 1, electrical power will be delivered to the mine through the Cow Portal from a 13.8 kV overhead power line originating from Bonanza Ledge Site. At Phase 2, power will be delivered from the main electrical room at the MSC to Valley Portal, while the power connection at Cow Portal will remain as a redundant power connection. Underground substations will transform the power to 600 volt (“V”) or 1,000 V depending on need or equipment to be supplied.

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

Fiber optics will be used to provide a data backbone to the mine. The mine network will then rely on 4G provided by radiant cables. This will allow for communication, automation of equipment, as well as ventilation-on-demand.

The layout of mine levels was designed to facilitate the automation of mucking and hauling. Each level will have one load out, which will allow for tele-remote loading of haulage trucks or loading of dumped waste material. Automation, or tele-operation of haulage trucks will be limited to dedicated drift or between shifts only. Automation and tele-remote for load haul dump/scooptram will be available any time as production levels will be isolated with barricades. By the end of 2027, all mucking operation on the production levels will be fully automated, with one operator for two scooptrams.

The mine dewatering network was designed to handle 10,666 cubic metres per day (“m³/day”). This system will also contribute to the dewatering of historic excavations.

The ventilation system has been designed to comply with British Columbia regulations. The airflow required to ventilate diesel engines was compiled using a 0.06 cubic metres per second (“m³/s”)/ kilowatt (“kW”) rate.

The system will be comprised of four independent intake fresh air raises, one exhaust raise and remaining exhaust through the main ramps and the Cow Portal. The total estimated airflow required to meet production is 715,000 cubic feet per minute (“cfm”) (337 m³/s).

Beginning in 2024, the total production rate will be 1,500 tpd (Phase 1), ramping up in 2027 to 4,900 tpd (Phase 2) (ore), with each zone contributing a different ratio to production over time.

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

The life of mine plan (“LOM”) has a 12-year mine life at maximum production rates from 1,500 tpd to 4,900 tpd. Production ramps-up to steady state of 4,900 tpd is achievable by the end of 2027, the third production year, with completion of the flotation circuit. The overall mine plan comprises 16.7 million tonnes (“Mt”) of ore that will be processed with an average grade of 3.8 grams per tonne (“g/t”) gold (“Au”). The mine will produce 7.1 Mt of waste from the development over the life of mine (“LOM”).

Table 1-3: Ore produced per year

Osisko Development Corp. NI 43-101 Technical Report   Feasibility Study for the Cariboo Gold Project

During pre-production, all development will be conducted by contractors. These contractors will provide the equipment used to develop lateral advance except for the roadheaders. ODV will take over the development and production work at the beginning of the production phase, gradually integrating its own equipment according to the needs of the operation.

The mine will operate 365 days/year with three different rosters for office and hourly personnel. A total of 298 employees (excluding staff and supervision) related to underground mining for operation and maintenance services for Phase 2 are anticipated in Wells.