Multi-Hole Drill Program Now Underway on "Case Lake West Cesium and Spodumene Pegmatite Project" in Ontario Bordering Power Metals Corp.'s Cesium Deposit

Rhea-AI Summary

Sienna Resources Inc. (SNNAF) has commenced a multi-hole drill program at its 100% owned 'Case Lake West Cesium and Spodumene Pegmatite Project' in Ontario. The project, spanning approximately 7,850 contiguous acres, borders Power Metals Corp.'s Case Lake deposit, which recently reported high-grade cesium mineralization up to 20.67% Cesium Oxide and tantalum grades reaching 5328ppm.

The company has also expanded its portfolio with several strategic acquisitions including:

• Stonesthrow Gold Project (31,718 acres)
• Uranium Town Project (10,357 acres) bordering Denison Mines
• Dragon Uranium Project (23,134 acres) bordering Cameco
• Atomic Uranium Project (55,440 acres) in Saskatchewan's Athabasca Basin
• Elko Lithium Project (1,830 acres) in Nevada
• Multiple Clayton Valley lithium projects near Tesla's Gigafactory

Positive

• Launch of new drill program at Case Lake West Project
• Strategic location adjacent to high-grade cesium discovery (20.67% Cs2O)
• Significant land package expansion across multiple projects
• Portfolio diversification across critical minerals (cesium, lithium, uranium)

Negative

• No proven mineralization yet on company's properties
• Early-stage exploration with no guaranteed results

Vancouver, British Columbia--(Newsfile Corp. - March 6, 2025) - Sienna Resources Inc. (TSXV: SIE) (OTC Pink: SNNAF) (FSE: A1XCQ0) ("Sienna" or the "Company") is pleased to announce that the multi- hole drill program is now underway on Sienna's 100% owned 'Case Lake West Cesium and Spodumene Pegmatite Project' in Ontario.

Jason Gigliotti, President of Sienna Resources, stated, "We are extremely pleased and excited to finally be underway on a drill program. It has been a long time since Sienna has drilled. The 'Case Lake West Cesium and Spodumene Pegmatite Project' has potential for cesium. When you consider that this project directly borders Power Metals Corp., whose shares increased approximately 300% in February based on their Case Lake deposit news, we couldn't be more excited about getting boots on the ground. These next few weeks/months will be a watershed mark for Sienna as the drilling occurs."

The 'Case Lake Cesium Project', owned by Power Metals Corp., is a highly prospective lithium, cesium, and tantalum (LCT) project in northeastern Ontario, Canada. Here are some of the highlights:

• High-grade mineralization: Recent drilling programs have consistently confirmed high-grade cesium mineralization, with standout results including up to 20.67% Cesium Oxide (Cs₂O). Exceptional Tantalum grades of up to 5328ppm have also been recorded.
• Shallow mineralization: The cesium mineralization is often found at shallow depths, which could make the project more economically viable.
• Multi-element potential: In addition to cesium, the project also contains significant lithium and tantalum mineralization, further enhancing its value.
• World-class asset: The Case Lake project is considered a world-class asset due to the high grades and significant size of the deposit.
• Strategic importance: The project's high-grade cesium and tantalum resources are strategically important for meeting the growing global demand for these critical minerals in advanced technologies.

Overall, the Case Lake Cesium project is a promising project with the potential to become a significant supplier of cesium, lithium, and tantalum. Management cautions that past results or discoveries on properties in proximity to Sienna may not necessarily be indicative of the presence of mineralization on the company's properties.

Sienna Resources Ownership Map

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About Sienna Resources Inc.

Sienna has significantly increased acreage of the "Stonesthrow Gold Project", consisting now of approximately 31,718 contiguous acres prospective for gold. Sienna has also recently acquired the "Case Lake West Cesium and Spodumene Pegmatite Project" in Larder Lake Mining division of Ontario, Canada roughly 100 km north of Kirkland Lake, NE Ontario. This project consists of approximately 7,850 contiguous acres prospective for Cesium and Spodumene Pegmatites. Sienna has also just acquired the 10,357 acre "Uranium Town Project" bordering Denison Mines Corporation , the now 23,134 contiguous acre "Dragon Uranium Project" bordering Cameco Corporation, and the 55,440 acre "Atomic Uranium Project" in the world renowned Athabasca Basin of Saskatchewan. Also, Sienna has the "Elko Lithium Project" in Elko County, Nevada consisting of approximately 1830 contiguous acres directly bordering Surge Battery Metals' "Nevada North Lithium Project" in Elko County, Nevada who announced the highest-grade lithium deposit in the USA. Sienna is also one of the larger landholders in Clayton Valley Nevada. Sienna's Clayton Valley projects include the Blue Clay Lithium Project, the Silver Peak South Project, and the Clayton Valley Deep Basin Lithium Project. Clayton Valley is home to the only lithium production in North America, being Albemarle Corp's Silver Peak deposit. This project is also near Tesla Motors Inc.'s Gigafactory in Nevada. On March 18, 2021, Schlumberger New Energy Venture announced the development of a lithium extraction pilot plant with a strategic partnership with Pure Energy. Management cautions that past results or discoveries on properties in proximity to Sienna may not necessarily be indicative of the presence of mineralization on the company's properties.

We seek Safe Harbor.

Qualified Person:

Mr. Frank Bain, PGeo, a qualified person as defined by National Instrument 43-101 has reviewed and approved the scientific and technical disclosure contained within this news release.

If you would like to be added to Sienna's email list, please email info@siennaresources.com for information or join our twitter account at @SiennaResources.

Contact Information
Tel: 1.604.646.6900
Fax: 1.604.689.1733
www.siennaresources.com
info@siennaresources.com

"Jason Gigliotti"
President, Director
Sienna Resources Inc.

Statements in this news release that are not historical facts are forward-looking statements. Forward-looking statements are statements that are not historical, and consist primarily of projections - statements regarding future plans, expectations and developments. Words such as "expects", "intends", "plans", "may", "could", "potential", "should", "anticipates", "likely", "believes" and words of similar import tend to identify forward-looking statements. Forward-looking statements in this news release include uncertainty of exploration and development plans regarding the property; commodity price fluctuations; political or economic instability and regulatory changes; currency fluctuations, the state of the capital markets; uncertainty in the measurement of mineral reserves and resource estimates; the Company's ability to attract and retain qualified personnel and management; potential labour unrest; reclamation and closure requirements for mineral properties and the availability of capital to fund the Company's projects, as well as other risks and uncertainties identified under the heading "Risk Factors" in the Company's continuous disclosure documents filed on SEDAR+. You are cautioned that the foregoing list is not exhaustive of all factors and assumptions which may have been used. The Company cannot assure you that actual events, performance or results will be consistent with these forward-looking statements, and management's assumptions may prove to be incorrect. These forward-looking statements reflect current expectations regarding future events and operating performance and speak only as of the date hereof and the Company does not assume any obligation to update forward-looking statements if circumstances or management's beliefs, expectations or opinions should change other than as required by applicable law. For the reasons set forth above, you should not place undue reliance on forward-looking statements.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this press release.

To view the source version of this press release, please visit https://www.newsfilecorp.com/release/243516

FAQ

What are the recent drilling results from SNNAF's Case Lake West Cesium Project?

The drill program has just started and results are pending. The adjacent Power Metals property has shown cesium grades up to 20.67% and tantalum grades up to 5328ppm.

How many acres does SNNAF's Case Lake West Cesium Project cover?

The Case Lake West Cesium and Spodumene Pegmatite Project covers approximately 7,850 contiguous acres in Ontario.

What other major projects does SNNAF currently own as of March 2025?

SNNAF owns the Stonesthrow Gold Project (31,718 acres), multiple uranium projects in Saskatchewan totaling over 88,000 acres, and several lithium projects in Nevada including the Elko Project.

Where is SNNAF's Case Lake West Project located relative to Power Metals' property?

The Case Lake West Project directly borders Power Metals Corp.'s Case Lake deposit in northeastern Ontario, approximately 100 km north of Kirkland Lake.