SAN ANTONIO GOLD PROJECT

Project Description

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The San Antonio Project is located in the state of Sonora, Mexico including the past producing Luz de Cobre oxide copper mine. The gold potential of the asset has never been properly evaluated, and Osisko Development will focus on amending existing permits to transition the mine production to a gold heap leach operation.

The MRE incorporates five deposits, Sapuchi, California, Golfo de Oro, High Life and Calvario, as part of what comprises 2.8 km of the 10.0 km within the Sapuchi-Cero Verde trend of the San Antonio Project. The deposits are constrained within a geologic model of the hydrothermal breccia, the main mineralization control known to date. Additional drill targets remain underexplored on the property and new exploration drilling is recommended to verify historic data and potentially add new resource. Further infill and exploration drilling is recommended on the Project.

San Antonio Gold Project Highlights

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Primary Commodity:	Gold
Location:	Sonora, Mexico Located 160 km from airport and towns of Hermosillo and Obregon
Land Package:	11,338 ha of mineral rights
Status:	Construction of a leach pad and carbon in column plant Stockpile has a total of 1.1 M tonnes with an average grade of 0.57 g/t Au. Processing of the stockpile began in Q4 2021 and currently, 680,000 tonnes of mineralized material has been placed and processed.

The Company cautions that the decision to process the stockpile at Sapuchi Minera has been taken without the benefit of a feasibility study, or reported mineral resources or mineral reserves, demonstrating economic and technical viability, and, as a result there may be increased uncertainty of achieving any particular level of recovery of material or the cost of such recovery. The Company cautions that historically, such projects have a much higher risk of economic and technical failure. There is no guarantee that production will continue as anticipated or at all or that anticipated production costs will be achieved. The failure to continue production would have a material adverse impact on the Company’s ability to generate revenue and cash flow to fund operations. Failure to achieve the anticipated production costs would have a material adverse impact on the Company’s cash flow and potential profitability. The Company cautions that historically, such projects have a much higher economic or technical risks. In continuing current operations at Sapuchi Minera, the Company will not be basing its decision to continue such operations on a feasibility study, or reported mineral resources or mineral reserves demonstrating economic and technical viability.

Location

Exploration Map

Deposit Zones

Project’s Mineral Resources

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INDICATED:

Deposit	Weathering Zone	Tonnes (Mt)	Au (g/t)	Ag (g/t)	Au Ounces (000)	Ag Ounces (000,000)
Deposit	Weathering Zone	Tonnes (Mt)	Au (g/t)	Ag (g/t)	Au Ounces (000)	Ag Ounces (000,000)
California	Oxide	0.6	0.93	2.8	17	0.05
	Transition	0.2	0.79	3.3	6	0.02
	Sulphide	3.1	1.31	2.4	130	0.23
	Total	3.9	1.22	2.5	153	0.31
Golfo de Oro	Oxide	0.2	1.07	2.8	7	0.02
	Transition	0.1	1.19	2.8	6	0.01
	Sulphide	5.3	1.46	2.5	249	0.42
	Total	5.7	1.44	2.5	262	0.46
Sapuchi	Oxide	1.9	0.85	3.6	53	0.22
	Transition	1.4	1.04	3.6	47	0.16
	Sulphide	2.1	0.94	3.4	62	0.22
	Total	5.4	0.93	3.5	162	0.61
Total	Oxide	2.7	0.89	3.4	77	0.3
	Transition	1.8	1.02	3.5	59	0.2
	Sulphide	10.4	1.31	2.6	441	0.88
	Total	14.9	1.2	2.9	576	1.37

INFERRED:

Deposit	Weathering Zone	Tonnes (Mt)	Au (g/t)	Ag (g/t)	Au Ounces (000)	Ag Ounces (000,000)
Deposit	Weathering Zone	Tonnes (Mt)	Au (g/t)	Ag (g/t)	Au Ounces (000)	Ag Ounces (000,000)
California	Oxide	0.4	0.68	2.1	8	0.02
	Transition	0.1	0.85	2.6	4	0.01
	Sulphide	1.1	1.27	3.8	46	0.14
	Total	1.6	1.1	3.3	58	0.17
Golfo de Oro	Oxide	0.5	0.8	3	12	0.04
	Transition	0.2	0.93	3.4	5	0.02
	Sulphide	5.7	1.29	2.5	237	0.46
	Total	6.4	1.24	2.5	254	0.52
High Life	Oxide	0.5	0.84	4.2	14	0.07
	Transition	0.2	0.73	4.5	4	0.02
	Sulphide	0.1	0.9	8.3	4	0.04
	Total	0.8	0.83	4.9	22	0.13
Sapuchi	Oxide	3.2	0.74	3.7	75	0.37
	Transition	1.6	0.92	3.6	48	0.19
	Sulphide	2.8	0.92	4.1	84	0.37
	Total	7.6	0.85	3.8	208	0.94
Calvario	Oxide	0.1	0.53	0	2	0
	Transition	0	0.55	0	0	0
	Sulphide	0.0	0.0	0.0	0.0	0.00
	Total	0.1	0.53	0	2	0
Total	Oxide	4.6	0.74	3.5	111	0.51
	Transition	2.1	0.9	3.6	61	0.24
	Sulphide	9.8	1.18	3.2	371	1
	Total	16.6	1.02	3.3	544	1.76

Mineral Resource Estimate notes:

Rodrigo Calles, of Servicios Geológicos IMEx, S.C., William Lewis and Alan S J San Martin, of Micon International Limited have reviewed and validated the mineral resource estimate for Sapuchi, Golfo de Oro, California, High Life and Calvario deposits. All are independent “Qualified Persons” (as defined in NI 43-101) responsible for the 2022 MRE. The effective date of the mineral resource estimate is June 24th, 2022.
Specific extraction methods are used only to establish reasonable cut-off grades for various portions of the deposit. No Preliminary Economic Analysis, Pre-Feasibility Study or Feasibility Study has been completed to support economic viability and technical feasibility of exploiting any portion of the mineral resource, by any particular mining method.
The mineral resources disclosed in this press release were estimated using the Canadian Institute of Mining, Metallurgy and Petroleum (“CIM”) standards on mineral resources and reserves definitions, and guidelines prepared by the CIM standing committee on reserve definitions and adopted by the CIM council.
The calculated economic cut-off grade for the resource in: Oxides (70% recovery) is 0.27 g/t Au, Transition and sulphides (90% recovery) is 0.44 g/t Au
Mineral resources are not mineral reserves and do not have demonstrated economic viability.
Geologic modeling was completed by Osisko Development geologist Gilberto Moreno. The MRE was completed by Geologist Leonardo Souza, MAusIMM (CP) of Talisker Exploration Services, under the supervision of Rodrigo Calles, of Servicios Geológicos IMEx, S.C., William Lewis and Alan S. J. San Martin, of Micon International Limited
The estimate is reported for a potential open pit scenario and with USD assumptions. The cut-off grades were calculated using a gold price of $1,750 per ounce, a CAD:USD exchange rate of 1.3; mining cost of $2.95/t; processing cost of $4/t for oxides and $13.0/t for transition and sulphides; and general and administration costs of $2.50/t. The cut-off grades should be re-evaluated in light of future prevailing market conditions (metal prices, exchange rate, mining cost, etc.).
A density of 2.55 g/cm³ was established for all oxide zones, 2.69 g/cm³ for transition zones and 2.74g/cm³ for the sulphide zones.
Resources for Sapuchi, Golfo de Oro, California, High Life and Calvario were estimated using Datamine Studio RM 1.3 software using hard boundaries on composited assays (3.0 m for all zones). Ordinary Kriging interpolation method was used in a with a parent block size = 10m x 10m x 5m.
Results are presented in-situ. Ounce (troy) = metric tons x grade / 31.10348. Calculations used metric units (metres, tonnes, g/t). The number of metric tons 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;
Neither the Company, Servicios Geológicos IMEx, S.C., nor Micon International Limited. is aware of any known environmental, permitting, legal, title-related, taxation, socio-political, marketing or other relevant issue that could materially affect the mineral resource estimate other than disclosed in this press release.