• Average annual gold production of 273,000 ounces for 19-years, including peak average annual production of 316,000 ounces over the first five years, and a maximum annual production of 325,000 ounces in Year 15.

• 5.2 million ounces of gold production over the 19 years of conceptual mine life ("CML").

• Base Case After-Tax NPV_5% of C$1.36 billion (US$1.01 billion) and IRR of 13.4% at US$2,500/oz gold.

• Spot Price After-Tax NPV_5% of C$3.30 billion (US$2.46 billion) and IRR of 24.0% at US$3,200/oz gold.

• 2025 MRE (as defined herein): 4.0 million ounces from 140.4 Mt grading 0.89 g/t Au in the Indicated category and 7.0 million ounces from 200.3 Mt grading 1.08 g/t Au in the Inferred category.

• 2025 PEA (as defined herein) is preliminary in nature and includes inferred mineral resources that are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as mineral reserves, and there is no certainty that the 2025 PEA will be realized. Mineral resources that are not mineral reserves do not have demonstrated economic viability.

Toronto, Ontario--(Newsfile Corp. - May 15, 2025) - STLLR Gold Inc.(TSX: STLR) (OTCQX: STLRF) (FSE: O9D) ("STLLR" or the "Company") announces the summary results of the updated Mineral Resource Estimate ("2025 MRE") and updated Preliminary Economic Assessment ("2025 PEA") for its 100%-owned Tower Gold Project ("Tower" or the "Project") located in the prolific Timmins Mining Camp in Ontario, Canada. The 2025 MRE was prepared by InnovExplo (a member of Norda Stelo) and the 2025 PEA was compiled by G Mining Services ("GMS"). Table 1: 2025 PEA¹ Economics*

Potential Economics	Gold Price Assumption
	US$2,500/ozBase Case	US$3,200/oz Spot
Pre-tax internal rate of return ("IRR")(%)	16.1%	28.6%
After-tax IRR	13.4%	24.0%
Pre-tax net present value at 5% discount rate ("NPV5%")(C$M)	C$2,118	C$4,961
After-tax NPV5% (C$M)	C$1,355	C$3,298
CML after-tax free cash flow ("FCF")(C$M)2	C$3,438	C$6,739
FX rate assumption (USD/CAD)	1.34	1.34
After-tax NPV5%/Initial Capex ratio	0.7x	1.8x
After-tax Payback period (years)	5.8	2.9

*Figures may vary slightly due to roundingTable 2: 2025 PEA¹: Conceptual Mine Plan Summary*

Metrics	CML Total	Per Unit
Conceptual Mine Plan
CML	19 years
2025 MRE conversion to conceptual mine plan	52%
Total mineralized material (million tonnes "Mt")	176.9 Mt	9.5 Mtpa3/26,030 tpd3
OP material during ramp-up	1.4 Mt
OP	148.8 Mt	7.8Mtpa3/21,370 tpd3
UG	26.6 Mt	1.7Mtpa3/4,660 tpd3
Total OP waste rock mined (Mt)	652.7 Mt
Total OP overburden tonnes ("OVB") mined (Mt)	288.3 Mt
Total OP waste (waste rock + OVB)	940.9 Mt
Strip ratio, excluding OVB	4.3
Strip ratio, including OVB	6.3
Average mill gold head grade ("g/t Au")	0.99 g/t Au
CML OP production	0.75 g/t Au
CML UG Production	2.35 g/t Au
Average mill recovery rate (%)	92.7%
Total potential payable gold production, excluding pre-production (thousand ounces "Koz")	5,191 Koz	273 Koz/year
Pre-production gold recovered, OP ramp-up	43 Koz
OP productionUG Production	3,326 Koz1,868 Koz	175 Koz/year98 Koz/year
Capex and Opex
Initial Capex (with contingency) (C$ millions "M")	C$1,873 M
Pre-production revenue (C$M)	C$144.6 M
Sustaining Capex4 (excluding Closure/Salvage)	C$1,723 M	C$91 M/year
Total Cash Costs5	C$8,901 M	C$1,715/oz (US$1,280/oz)
All-In Sustaining Cost ("AISC")6	C$10,700 M	C$2,059/oz (US$1,537/oz)
All-In Costs ("AIC")6	C$12,575 M	C$2,403/oz (US$1,793/oz)

*Figures may vary slightly due to roundingSTLLR President and CEO Keyvan Salehi, P.Eng. commented: "Tower is one of Canada's largest undeveloped gold projects, with size and scale matched only by a few Canadian gold projects. The 2025 PEA showcases the potential to produce 273,000 ounces of gold annually over 19 years, with peak production of 325,000 ounces. We believe the 2025 PEA delivers compelling economics with defensible capital and operating cost estimates. We designed the conceptual mine plan to maximize the output, which we believe is the best path to advance the Project and deliver long-term value. Furthermore, it is also our view that the geological environment hosting the Project continues along strike and...