Seabridge Gold announced the results of an updated Preliminary Feasibility Study (the "2022 PFS") for its 100% owned KSM project located in northern British Columbia, Canada. The 2022 PFS shows a considerably more sustainable and profitable mining operation than its 2016 predecessor, now consisting of an all open pit mine plan that includes the Mitchell, East Mitchell and Sulphurets deposits only. The primary reasons for the improvements in the plan arise from the acquisition of the East Mitchell open pit resource and an expansion to planned mill throughput.

The many design improvements over the 2016 PFS include a smaller environmental footprint, reduced waste rock production, reduced green house gas emissions by electrification of the mine haul fleet, a 50% increase in mill throughput, and the elimination of capital-intensive block cave mining. The 2022 PFS was prepared by Tetra Tech Inc. ("Tetra Tech"), the firm that had also authored the 2016 PFS. The 2022 PFS results released herein propose mining only 25% of the KSM resource inventory and do not include material from the copper-rich Kerr and Iron Cap deposits.

An analysis of a stand-alone development of these deposits will be included as a Preliminary Economic Assessment ("PEA") forming a separate part of the NI 43-101 Technical Report to be filed within the next 45 days. Notable improvements in the Base Case 2022 PFS compared to the Base Case 2016 PFS include: Proven and probable gold reserves increase 22%, from 38.8 million ounces to 47.3 million ounces, due to higher gold grades added from the East Mitchell deposit; Mill throughput expands from 130,000 tonnes per day ("tpd") to 195,000 tpd; Waste to ore strip ratio reduced by 23% to approximately 1:1; A 90% increase in average annual gold production, 22% increase in annual copper production, 36% increase in annual silver production, and a 363% increase in annual molybdenum production; Total capital of USD 10.5 billion is reduced to USD 9.6 billion with increases from inflation and mill expansion being wholly offset by the elimination of block cave mining from the PFS plan; Initial capital increases from USD 5.0 billion to USD 6.4 billion primarily due to inflation; A 20 year reduction in mine life from 53 Years to 33 years due to the increased mill throughput supplied by higher open pit production; Total after tax net cash flow increases from USD 10.0 billion to USD 23.9 billion; After tax NPV(5%) increases from USD 1.5 billion to USD 7.9 billion; After tax IRR increases from 8.0% to 16.1%; Payback period drops from 6.8 years to 3.7 years. The 2022 PFS envisages an open pit mine operation that is scheduled to operate for 33 years.

Ore delivery to the mill is increased from an initial 130,000 metric tpd to 195,000 tpd in Year 3. Over the entire 33-year mine life, ore will be fed to a flotation and gold extraction mill. The flotation plant will produce a gold/copper/silver concentrate for transport by truck to a nearby seaport at Stewart, B.C. for shipment to Pacific Rim smelters. Metallurgical projections supported by extensive metallurgical testing project a copper concentrate with an average copper grade of 24% and a high gold (64 g/t) and silver (177g/t) content, making it readily saleable.

A separate molybdenum concentrate and gold-silver doré will be produced at the KSM processing facility. The 2022 PFS uses previously disclosed resource estimates that are based on USD 1,300 per ounce gold, USD 3.00 per pound copper, USD 20.00 per ounce silver and USD 9.70 per pound molybdenum. In addition, the resources are constrained by conceptual mining shapes.

Measured and Indicated Mineral Resources at KSM are estimated at 5.4 billion tonnes grading 0.51 grams per tonne gold, 0.16% copper, 2.4 grams per tonne silver, and 63 ppm molybdenum (88.3 million ounces of gold, 19.4 billion pounds of copper, 414 million ounces of silver, and 742 million pounds of molybdenum). An additional 5.7 billion tonnes are estimated in the Inferred Mineral Resource category grading 0.36 grams per tonne gold, 0.28% copper, 2.2 grams per tonne silver, and 33 ppm molybdenum (65.6 million ounces of gold, 35.1 billion pounds of copper and 406 million ounces of silver, and 415 million pounds of molybdenum). Updated Mineral Reserves for the project are based on open pit mining of the Mitchell, East Mitchell and Sulphurets deposits.

Waste to ore cut-offs were determined using a net smelter return ("NSR") for each block in the model. NSR is calculated using prices and process recoveries for each metal accounting for all off-site losses, transportation, smelting and refining charges. Metal prices of USD 1,300 per ounce gold, USD 3.00 per pound copper, USD 20 per ounce silver and USD 9.70 per pound molybdenum and a foreign exchange rate of USD 0.79 per CAD have been used in the NSR calculations.

Lerchs-Grossman ("LG") pit shell optimizations were used to define open pit mine pit limits in the 2022 PFS. Open pit designed phases use updated geotechnical design criteria based on recent site investigation programs. Mineral Reserves have been estimated using the updated pit designs. The open pit minimum NSR cut-off grade is varied between CAD 11/t to CAD 25/t and considers the estimated process operating cost of CAD 10/t. Process operating costs include plant processing (including crushing/conveying costs where applicable), G&A, surface service, tailings, and water treatment costs.

A premium cut-off grade of CAD 25/t is used until the end of Year 5 to maximize the NPV and minimize the time to payback of initial capital.