Osisko Development Announces Preliminary Economic Assessment FOR the Cariboo GOLD Project and Refiling Certain Continuous Disclosure Documents
OSISKO DEVELOPMENT ANNOUNCES PRELIMINARY ECONOMIC ASSESSMENT FOR THE
CARIBOO GOLD PROJECT AND REFILING CERTAIN CONTINUOUS DISCLOSURE DOCUMENTS
MONTREAL, May 24, 2022 – Osisko Development Corp. (“ Osisko Development ” or the “ Company”)
(TSX.V-ODV) is pleased to announce the results from its Preliminary Economic Assessment (“PEA” or the
“Study”) completed by BBA Engineering Ltd., consultants for the Cariboo Gold Project (“Cariboo” or the
“Project”) in Central British Columbia (“BC”).1
The PEA provides a technical and economic update based on the updated underground Mineral Resource
Estimate (“MRE”) from the 2021 diamond drill campaign and current costs and economic estimates. The
MRE contains 27.1 million tonnes (“ Mt”) at an average grade of 4.0 grams per tonne gold (“ g/t Au”) for a
total of 3.47 million ounces (“ M oz”) in the Measured and Indicated Category (consisting of a Measured
Resource of eight thousand ounces of gold (47,000 tonnes grading 5.1 g/t Au) and an Indicated Resource
of 3.46 million ounces of gold (27 mill ion tonnes grading 4.0 g/t Au)) and 14.4 Mt at a grade of 3.5 g/t Au
for a total of 1.6 M oz in the I nferred category (Table 6). These mineral resources have informed an 8,000
tonnes per day (“tpd") scenario over a 12-year operating mine life, which highlights the potential growth of
the Cariboo Gold Project. The PEA is available on the Company's website and the profile of the Company
at www.sedar.com. The Company notes that mineral resources are not mineral reserves as they do not
have demonstrated economic viability . The Company notes that a preliminary economic assessment is
preliminary in nature, it includes inferred mineral resources that are considered too speculative geologically
to have economic consideration applied to them that would enable them to be categorized as mineral
reserves, and there is no certainty that the preliminary economic assessment will be realized.
The PEA illustrates potential economics for a low cost, large scale, underground gold mine, with industry
leading operating costs. The study outlines total gold production of 2.8 million gold ounces, resulting in an
average annual gold production profile of 236,000 ounces with an All-In-Sustaining Cost (“AISC”) per ounce
of $1,222 (US$962) (AISC is a non-IFRS measure – please see under the heading "Non-IFRS Measures"
below). The Project after-tax net present value (“NPV”) (5% discount rate) is $764 million with an after-tax
internal rate of return (“ IRR”) of 21.4% at a gold price of $2 ,223 (US$1,750) per ounce, and $912 million
and 24.5% at a spot gold price for May 19, 2022 at $2,343 (US$1,845) per ounce.
The PEA recommends that the C ompany continues to work towards a f easibility study and completes the
following steps:
1. Incorporate all drilling results from 2021 and 2022 currently in progress in the resources.
2. Complete the development of the ramp and extraction of the 10,000- tonne (“t”) bulk sample that will
help support the evaluation and testing of the proposed roadheader mining equipment and ore sorting
equipment and gain experience to maximize the full potential of these technologies .
3. Integrate the information and experience gained with the bulk sample into the development strategy of
the mine and the feasibility study planning.
4. Continue exploration program with drilling (infill and exploration), geological mapping, and grab
sampling to test the depth extensions of known high-grade vein corridors and identify new targets.
The Company plans to proceed with a feasibility study in connection with the work plan recommended by
the PEA.
The Company advises that this clarifying news release is being issued at the request of the Autorité
des marchés financiers fol lowing a continuous disclosure review. Certain previous economics
described in the Table 1 below in relation to the Project disclosed by the Company were not
supported by a technical report prepared in accordance with National Instrument 43-101 Standards
1 Unless otherwise indicated, all amounts are expressed in Canadian Dollars.
of Disclosure for Mineral Projects (“NI 43-101”) and are superseded by the economics set out in the
current NI 43- 101 report and the Company cautions the reader not to rely on such previous
economics. The Company is also filing a restated version of its annual managements' discussion
and analysis and annual information form to, as applicable, remove the unsupported technical
information and qualify other disclosure.
The previous economics were made public by the Company in connection with the environmental
assessment for the Cariboo Project. These economics were prepared in accordance with the requirements
for major projects in British Columbia to be assessed for potential environmental, social, economic, health
and cultural effects by the Environmental Assessment Office, as required by the Environmental Assessment
Act (British Columbia) (the " Environmental Assessment Act "). The previous economics do not include
numbers verified to a NI 43-101 standard, and do not include the suite of investor focused economics,
including the IRR and NPV for the project. These previous economics were to engineering standards. You
will find below a table showing the differences between the previous economics and the economics
contained in the PEA.
Table 1: Project Economics
Information Previous economics PEA economics Explanation of the
differences
Production Rate (tpd) 4,750 tpd Up to 8,000 tpd Based on the Company’s
initial expectation a 4,750
tpd mine was used for the
environmental
assessment but in
accordance with the
MRE, its is expected that
production could increase
during the life of the mine
to up to 8,000 tpd
Mine Life 16 years 12 years Higher production rate
Initial Capital Cost and
Total Capital Cost
Projected initial capital
cost of $400 to $450
million and total capital
cost over the life of
mine estimated at just
under $900 million
Projected initial
capital cost of $122
million, expansion
capital cost of $716
million and total
capital over the life
of mine estimated at
$1,364 million
The differences are
influenced by number of
factors including:
• higher production
rate
• additional
resources
• additional
environmental
and engineering
data
• inflation.
The Key Operational Findings of the PEA are:
o Phased construction approach with an initial construction enabling a 2,000-tpd mine and an
expansion raising the throughput at 8,000 tpd
o Average life of mine (“LOM”) annual production of 236,000 ounces per annum
o Peak production of 316,000 ounces and average of 297,000 ounces when operating at 8,000tpd
o LOM AISC per ounce of $1,222 (US$962)
o Projected to have an initial mine life of 12 years
o First gold pour targeted for Q1 2024
The Key Financial Forecast of the PEA are (at a base case gold price of US$1,750/oz):
o Initial capital requirement of $121.5 million
o Expansion capital requirement of $716.1 million
o LOM pre-tax undiscounted free cash flow of $2.0 billion (post-tax $1.3 billion)
o Annual pre-tax free cash flow averages $167 million over 12 years of commercial production
o Annual after-tax free cash flow of $112 million over 12 years of commercial production
o After-tax NPV (5%) of $764M
o After-tax IRR of 21.4%
o Payback period pre-tax of 5.8 years (post-tax 6.0 years)
Sean Roosen, Chair & Chief Executive Officer of Osisko Development, commented: “The PEA builds
on previous technical work while incorporating the results of extensive drilling together with several
improvements and optimizations. The capital and operating cost estimates rely on recent budgetary quotes
reflecting the current cost envir onment and our project execution approach. The recent inflation and
difficulty with the supply chain has put to the forefront the challenges the mining industry is facing. The
Project provides an attractive potential gold production profile of approximatel y 297,000 ounces per year
when operating at 8,000tpd over an 8-year period, making it one of the premier gold development projects
in North America and key socio-economic contributor to the Cariboo region, particularly in Wells, Quesnel,
and surrounding areas, and the Province of BC. This PEA highlights a phased approach with an initial
project able to produce 75,000oz/year at low capital cost, but most importantly, providing us access to the
deposits from underground to do further exploration and seek to unlock more potential value outside of the
current mine design that has an average mine depth of 350 meters. We believe t his is a more prudent
approach in the actual economic contex t without compromising the full potenti al of the Cariboo Gold
Project.”
Table 2: Key Economic Outputs of the Study
Description Units
Production Date (Operations Period)
Mine Life year 12
Average Process Throughput tpd 6,424
Average Process Throughput MMt2/ year 2,346
Gold Head Grade g/t 3.40
Contained Gold koz3 3,080
Recovery % 92.1
Total Gold Production koz 2,837
Average Annual Gold Production koz 236,000
Average Annual Full Years at 8,000tpd koz 297,000
Operating Costs (Average LOM)
Mining Cost $/t mined 52.73
Processing Cost $/t mined 24.00
Concentrate transport $/t mined 3.85
Tailings and Water Management $/t mined 5.81
G&A Cost
$/t mined 7.63
Total Site Operating Costs $/t mined 94.02
Total Site Operating Costs US$/oz 734.85
AISC US$/oz 961.6
Capital Costs
Initial Capital $ MM 121.5
2 MMt means millions of tonnes.
3 koz means thousand ounces.
Expansion Capital $ MM 716.1
Life of Mine Sustaining Capital $ MM 527.2
Total Capital Costs $ MM 1,364.84
Financial Evaluation
Gold Price Assumption US$/oz 1,750
USD:CAD FX Assumption x 1.27
After-Tax NPV (5%) $ MM5 763.8
After-Tax IRR % 21.4
Payback year 5.8
Figure 1: Average Annual Production Rate and Gold Production

Table 3: Sensitivity Analysis
Scenario Unit
Downside Au
Price Case Base Case
Spot Au Price
Case (May 19,
2022)
Upside Au
Price Case
Gold Price US$/oz 1,450 1,750 1,845 2,050
After-Tax NPV (5%) $ MM 288.2 763.8 912.4 1,231.0
After-Tax IRR % 11.2 21.4 24.5 31.2
LOM Free Cash Flow $ MM 697 1,342 1,546 1,988
LOM EBITDA $ MM 2,298 3,325 3,650 4,351
Payback years 7.6 6.0 5.6 4.9
Table 4: Operating Cost Summary
Operating Costs $/t Mined
Mining 52.73
Transportation 3.85
Processing (including underground
crushing, ore sorting and paste backfill) 24.00
Tailings, waste & water management 5.81
General & administration 7.63
Total 94.02
4 This amount doesn’t include the Closure cost and the Salvage Value of the equipment and infrastructures
5 MM means millions.
Table 5: Project Capital Cost Summary
Area Description
Total Capital
Cost ($ MM)
Mobile Equipment 10.6
Underground Mine 507.0
Water & Waste Management 101.1
Electrical & Communication 137.5
Surface Infrastructure 117.7
Mine Surface Infrastructure 10.3
Processing - Mine Site Complex 190.6
Processing - QR Mill 57.1
Construction Indirect Costs 86.9
Owner’s Costs 31.0
Contingency 98.6
Capitalized Operating Costs 16.4
Total 1,364.8
Closure Costs 18.5
Salvage Value -61.1
PEA Overview
The Company retained BBA Engineering Ltd. as lead consultants, along with other engineering consultants,
to complete the Study and prepare a technical report in accordance with NI 43-101.
The Project surface infrastructure and services are designed to support the operations at the Mine Site
Complex and at the Quesnel River Mill (“QR Mill”). The Project also includes off-site infrastructure, such as
a new 69 kV / 138 kV transmission line between the Barlow substation, near Quesnel, BC, and the Mine
Site Complex. Warehousing for major components and consumables will be provided by third parties in
Quesnel and / or Prince George.
The Project will be comprised of three different sites: the Mine Site Complex, near the District of Wells, BC,
the Bonanza Ledge Site, and the QR Mill.
Underground longhole longitudinal retreat with a combination of paste fill and cemented rockfill mining
methods will be used for the extraction of the economic mineable inventory, as it is the most economic, and
sustainable methodology. The Project is planned in two phases, Phase 1 is at 2,000 tpd for 2.5 years,
increasing during Phase II to an average production of 8,000 tpd over a 9.5- year LOM. This Report has
focused on five underground zones: Shaft Zone, Valley Zone, Cow Zone, Mosquito Zone and Lowhee Zone.
The mining zones are accessed via three main portals and are connected by an internal ramp system.
Property Description, Location and Access
The Project is located in the historic Wells - Barkerville mining camp of British Columbia and the Mineral
Claim Block extends for 77 kilometres (“km”) from northwest to southeast. The Project falls, in large portion,
within the towns of Wells. Wells is situated 74 km east of Quesnel, approximately 115 km southeast of
Prince George, and approximately 500 km north of Vancouver.
The Project consists of 412 mineral titles totalling 155,147.09 hectares across two contiguous property
blocks known as the Cariboo Main Block and the QR Mill Property. These mineral titles include mineral
claims, mineral leases, placer claims and placer leases. A net smelter return royalty of 5% payable to
Osisko Gold Royalties Ltd is the only royalty that applies to the Project.
Mineral Resource Estimate
• Measured and Indicated Resource of 3.4 M oz of gold (27.1 Mt grading 4.0 g/t Au)
• Inferred Mineral Resource of 1.6 M oz of gold in the Inferred category (14.4 Mt grading 3.5 g/t Au)
• The 2022 M ineral Resource Estimate includes eight deposit areas : Mosquito, Shaft, Valley, Cow,
Bonanza Ledge, BC Vein, Lowhee and KL
• The MRE is based upon over 650,000 metres (“m”) of diamond drilling from Osisko Development’s
2015 to 2021 drill programs and historically verified drill hole data for a total of 3,550 holes
• A total of 471 mineralized solids were used for the MRE: 109 solids for Cow, 100 for Valley, 93 for
Shaft, 75 for Mosquito, 47 for Lowhee, BC Vein and five splays (a total of 6 solids), 40 for KL, and
1 solid for Bonanza Ledge
• The Approach for the reasonable prospect for an eventual economical extraction for the MRE is met
using constrained, potentially mineable shapes, reflecting latest CIM Mineral Exploration Best Practice
Guidelines (CIM Exploration Guidelines, November 2019)
• The MRE includes the Cow–Island–Barkerville Mountain Corridor. The Cow -Island segment covers a
strike length of 3.7 km and a width of approximately 400 m, down to a vertical depth of 650 m below
surface. The Barkerville segment covers a strike length of 3.0 km and a width of approximately 500 m,
down to a vertical depth of 500 m below surface
• The BC Vein deposit is 1.7 km in strike length, 0.5 m to 37 m in thickness, and 400 m in depth
Table 6: Mineral Resource Estimate
Category Deposit
Tonnes Grade Ounces
‘000 (g/t Au) ‘000
Measured Bonanza Ledge 47 5.1 8
Indicated
Bonanza Ledge 32 4.0 4
BC Vein 1,030 3.1 103
KL 389 3.2 40
Lowhee 1,621 3.6 188
Mosquito 1,795 4.3 249
Shaft 11,139 4.3 1,531
Valley 4,403 3.8 536
Cow 6,645 3.8 811
Total Measured Resources 47 5.1 8
Total Indicated Mineral Resources 27,055 4.0 3,463
Inferred
BC Vein 461 3.5 53
KL 1,905 2.8 168
Lowhee 520 3.5 59
Mosquito 1,262 3.6 146
Shaft 5,730 3.9 725
Valley 2,135 3.4 235
Cow 2,394 3.1 236
Total Measured and Indicated Mineral Resources 27,102 4.0 3,470
Total Inferred Mineral Resources 14,407 3.5 1,621
Mineral Resource Estimate notes:
1. The independent and qualified persons for the Mineral Resource Estimates, as defined by NI 43- 101,
are Carl Pelletier, P.Geo., and Vincent Nadeau Benoit, P.Geo. (InnovExplo Inc.). The effective date of
the 2022 Mineral Resource Estimate is May 17, 2022.
2. These mineral resources are not mineral reserves as they do not have demonstrated economic viability.
3. The Mineral Resource Estimate conforms to the 2014 CIM Definition Standards on Mineral Resources
and Reserves and follows the 2019 CIM Estimation of Mineral Resources and Mineral Reserves Best
Practice Guidelines.
4. A total of 471 vein zones were modelled for the Cow Mountain (Cow and Valley), Island Mountain (Shaft
and Mosquito), Barkerville Mountain (BC Vein, KL, and Lowhee) deposits and one gold zone for
Bonanza Ledge. A minimum true thickness of 2.0 m was applied, using the grade of the adjacent
material when assayed or a value of zero when not assayed.
5. The estimate is reported for a potential underground scenario at a cut -off grade of 2.0 g/t Au, except
for Bonanza Ledge at a cut -off grade of 3.5 g/t Au. The cut -off grade for the Cow, Valley, Shaft,
Mosquito, BC Vein, KL, and Lowhee deposits was calculated using a gold price of USD1,600 per ounce;
a USD/CAD exchange rate of 1.30; a global mining cost of $50.41/t; a processing & transport cost of
$30.41/t; and a G&A + Environmental cost of $16.18/t. The cut-off grade for the Bonanza Ledge deposit
was calculated using a gold price of USD1,600 per ounce; a USD/CAD exchange rate of 1.30; a global
mining cost of $79.13/t; a processing & transport cost of $60.00/t; and a G&A + Environmental cost of
$51.65/t. The cut-off grades should be re-evaluated in light of future prevailing market conditions (metal
prices, exchange rate, mining cost, etc.).
6. Density values for Cow, Shaft, and BC Vein were estimated using the ID2 interpolation method, with a
value applied for the non-estimated blocks of 2.80 g/cm3 for Cow, 2.79 g/cm3 for Shaft, and 2.69 g/cm3
for BC Vein. Median densities were applied for Valley (2.81 g/cm 3), Mosquito (2.79 g/cm 3),
KL (2.81 g/cm3) and Lowhee (2.75 g/cm3). A density of 3.20 g/cm3 was applied for Bonanza Ledge.
7. A four-step capping procedure was applied to composited data for Cow (3.0 m), Valley (1.5 m), Shaft
(2.0 m), Mosquito (2.5 m), BC Vein (2.0 m), KL (1.75 m), and Lowhee (1.5 m). Restricted search
ellipsoids ranged from 7 to 50 g/t Au at four different distances ranging from 25 m to 250 m for each
deposit. High grades at Bonanza Ledge were capped at 70 g/t Au on 2.0 m composited data.
8. The mineral resources for the Cow, Valley, Shaft, Mosquito, BC Vein, KL, and Lowhee vein zones were
estimated using Datamine S tudioTM RM 1.9 software using hard boundaries on composited assays.
The OK method was used to interpolate a sub- blocked model (parent block size = 5 m x 5 m x 5 m).
Mineral resources for Bonanza Ledge were estimated using GEOVIA GEMSTM 6.7 software using hard
boundaries on composited assays. The OK method was used to interpolate a block model (block size
= 2 m x 2 m x 5 m).
9. Results are presented in situ. Ounce (troy) = metric tons x grade / 31.10348. Calculations used metric
units (metres, tonnes, g/t). The number of tonnes was rounded to the nearest thousand. Any
discrepancies in the totals are due to rounding effects. Rounding followed the recommendations as per
NI 43-101.
10. Other than as set out in the PEA, t he qualified persons responsible for this section of the technical
report are not aware of any environmental, permitting, legal, title, taxation, socio-economic, marketing,
political or other relevant factors that could materially affect the Mineral Resource Estimate.
Environmental Assessment
An Environmental Assessment for the Project was initiated with the submission and acceptance of an initial
project description in 2020, as per the Environmental Assessment Act , at a production rate of 4,750 tpd.
Issuance of an Environmental Assessment Cer tificate (“EAC”) is expected after successful review of the
Application. The use of the updated resources in the PEA demonstrates the potential growth of the Project
allowing for a scaled ramp up of activity to 8,000 tpd pending required permitting. Any changes to the
Certified Project Description (or activities/works not authorized by the EAC), resulting from the increased
production rate will first require an amendment to the Project EAC before proceeding to an updated detailed
design and ensuing permit amendment applications.
Community and Indigenous Engagement
Osisko Development recognizes that early and frequent engagement is key to our business success.
Through listening and open communication, we are better positioned to plan and design our projects in
ways that reduce potential environmental and social impacts. The Company actively engages with
Indigenous nations, the public, its employees, and local, regional, provincial, and federal governments and
agencies. We understand that the level of involvement and interest differs amongst different groups, and
we adjust communication strategies accordingly.
Engagement for the Project began in 2016. In October 2020, a Life of Project Agreement was signed
between Osisko Development and Lhtako Dené Nation, which includes commitments for training,
employment, and contracting opportunities. Agreements with Xatśūll First Nation and Williams Lake First
Nation are in negotiation. In July 2021, discussions with the Wells District and Council began to init iate a
Memorandum of Understanding ( “MOU”) between the town and Osisko Development, and a MOU was
signed in March 2022.
Qualified Persons
Vincent Nadeau-Benoit, P.Geo., and Carl Pelletier, P.Geo., of InnovExplo Inc. each of whom is a "qualified
person" within the meaning of NI 43- 101 and considered to be "independent" of Osisko Development for
purposes of Section 1.5 of NI 43-101, have reviewed and approved the contents of this news release.
Colin Hardie, P.Eng., of BBA Engineering Ltd., is a "qualified person" within the meaning of NI 43-101 and
considered to be "independent" of Osisko Development for purposes of Section 1.5 of NI 43- 101, has
reviewed and confirmed that the news release fairly and accurately reflects the information in the technical
report for which he is responsible.
Mathieu Belisle, P.Eng., of BBA Engineering Ltd. , is a "qualified person" within the meaning of NI 43- 101
and considered to be "independent" of Osisko Development for purposes of Section 1.5 of NI 43- 101, has
reviewed and confirmed that the news release fairly and accurately reflects the information in the technical
report for which he is responsible.
Éric Lecomte, P. Eng. , of InnovExplo Inc. , is a "qualified person" within the meaning of NI 43- 101 and
considered to be "independent" of Osisko Development for purposes of Section 1.5 of NI 43- 101, has
reviewed and confirmed that the news release fairly and accurately reflects the information in the technical
report for which he is responsible.
Tim Coleman, P.Eng. , of SRK Consulting (Canada) Inc., is a "qualified person" within the meaning of NI
43-101 and considered to be "independent" of Osisko Development for purposes of Section 1.5 of NI 43-
101, has reviewed and confirmed that the news release fairly and accurately reflects the information in the
technical report for which he is responsible.
Paul Gauthier, P. Eng. , of WSP Golder, is a "qualified person" within the meaning of NI 43- 101 and
considered to be "independent" of Osisko Development for purposes of Section 1.5 of NI 43- 101, has
reviewed and confirmed that the news release fairly and accurately reflects the information in the technical
report for which he is responsible.
Aytaç Göksu, P.Eng. , of WSP Golder, is a "qualified person" within the meaning of NI 43- 101 and
considered to be "independent" of Osisko Development for purposes of Section 1.5 of NI 43- 101, has
reviewed and confirmed that the news release fairly and accurately reflects the information in the technical
report for which he is responsible.
Thomas Rutkowski, P.Eng. , of WSP Golder , is a "qualified person" within the meaning of NI 43- 101 and
considered to be "independent" of Osisko Development for purposes of Section 1.5 of NI 43- 101, has
reviewed and confirmed that the news release fairly and accurately reflects the information in the technical
report for which he is responsible.
John Cunning, P.Eng. , of WSP Golder, is a "qualified person" within the meaning of NI 43- 101 and
considered to be "independent" of Osisko Development for purposes of Section 1.5 of NI 43- 101, has
reviewed and confirmed that the news release fairly and accurately reflects the information in the technical
report for which he is responsible.
Kristin Salzsauler, P.Geo. , of WSP Golder , is a "qualified person" within the meaning of NI 43- 101 and
considered to be "independent" of Osisko Development for purposes of Section 1.5 of NI 43- 101, has
reviewed and confirmed that the news release fairly and accurately reflects the information in the technical
report for which she is responsible.