Sage Potash Corp. (TSX-V: SAGE) (OTCQB: SGPTF) is pleased to announce a significant upgrade to its potash resource estimates after the successful completion of its Summer 2026 drill program at the Company’s flagship Sage Plain Potash Project in Utah’s Paradox Basin. The new Mineral Resource Estimate, as prepared by independent engineering firm RESPEC LLP, materially expands the inferred potash resource and allows the addition of measured and indicated resource categories.

Summary

• Measured Potash Resource of 54.3 million tonnes grading 41.31% KCl.
• Indicated Potash Resource of 171.8 million tonnes grading 41.37% KCl
• Inferred Potash Resource of 545.4million tonnes grading 41.53% KCl

Executive Comment

“Completion of the Summer 2026 drilling of the Peterson 1 Well and the resulting Mineral Resource Estimate mark a major milestone for the Company,” said Pat Varas, CEO of Sage Potash. “The results validate the project’s extensive potash resources and confirm the Paradox Basin’s potential to support a scalable, high-quality potash operation. The upgraded estimate provides a strong foundation for our next core objective: completing a Pre-Feasibility Study to demonstrate the viability and economic metrics of the Sage Plain Potash Project. We will now focus on optimizing the mining and processing plans, including the potential to scale up the project substantially from the preliminary economic assessment reported in September 2025.”

Resource Estimate

The Summer 2026 drilling of the Peterson 1 Well delivered high-grade thick intervals of both the Upper and Lower Cycle 18 potash beds. The new data confirms consistent lateral continuity of potash horizons, confirmation of high-grades and impressive thicknesses for solution mining.

Table 1.0 – Sage Plain Project Resource Estimate

1. MMT = Million Metric Tonnes.
2. Density of Sylvinite = 2.07 tonnes/m³.
3. In-Place Sylvinite is based on Area x Thickness.
4. Gross Resource based on 100% extraction ratio and 0% plant loss.
5. Measured Resource radius of influence is 0-750m.
6. Indicated Resource radius of influence is 750 – 2,000 m.
7. Inferred Resource radius of influence is 2,000 – 4,000 m.
8. Exclusions or deductions for unknown seismic anomalies are 25% of the area as no 3D seismic has been completed
9. The following deductions are anticipated, but not yet applied: A) Mining Parameter deductions for extraction ratio and cavern or plan loss; B) Economic Cut-offs from a project specific analysis. The appropriate deductions values are anticipated as outputs from further studies.
10. Potash Bed Inferred Resource uses a 5% K₂O cutoff to define the upper and lower contacts.
11. Average KCl Grades are the weighted average for the interval thickness based on core recovered and Gamma ray readings in instances of core removal for geomechanical testing or core losses (Johnson 1 hole Lower Bed only and eight 30 cm sections form Peterson 1 Well).

The upgraded resource estimate provides an overall 259% increase in tonnage compared to the resource estimate in the Preliminary Economic Assessment Technical Report (dated November6, 2025, with an effective date of September 8, 2025, and available on www.sedarplus.ca under the Company’s profile) as shown in Table 2.

Table 2.0 – Sage Plain Project Resource Estimate 2026 and 2025 Comparison

Resource classifications and estimates have been determined by RESPEC LLC of Grand Junction Colorado. RESPEC is the Qualified Professional (QP) as required by National Instrument 43-101, Standards of Disclosure for Mineral Projects (“NI 43-101″). Mr. Erik Hemstad – Principal Consultant with RESPEC commented, “RESPEC has been involved with the Sage Plain Project for many years and is pleased to provide this mineral resource estimate. We are also pleased to provide ongoing input on geological interpretation and appropriate potash solution mining techniques for this basin in general and the Sage Plain Project specifically. The Sage Plain Project is located within the heart of the Paradox Basin and is showing very strong potential as a potash producer in Utah.”

Next Steps

The Company will publish and file on Sedar+ a Technical Report in accordance with the requirements of NI43-101 within 45 days of this news release. Thereafter, the next phases of work will include:

• Advancement of solution-mining engineering and process design including determination of solution mining and plant throughput capacity
• Continued environmental study work and permitting activities for the new throughput capacity design
• Ongoing collaboration with regional stakeholders and local communities
• Trade-off and availability studies for the provision of power, water and transportation logistics to the Sage Plain site.

The Company plans to summarize the above facets and demonstrate the financial viability of the project in a Pre-Feasibility Study.

Qualified Person

The scientific and technical information contained in this news release has been reviewed and approved by Eric Hemstad, PE, a Qualified Person as defined by NI 43-101. Mr. Hemstad is a Consulting PE at RESPEC Company, LLC and is independent of Sage Potash.

About Sage Potash Corp.

Sage Potash Corp. is dedicated to the development of its flagship Sage Plain Potash Project, located in the Paradox Basin, Utah. With a large and high-grade resource base, the Company is advancing toward its goal of establishing a secure and sustainable domestic potash production platform in the United States. Sage Potash is committed to food security, environmental stewardship, and creating value for shareholders and stakeholders alike.