Sienna Resources Inc. Commences Drilling on the Esmeralda County Gold Project, Walker Lane, Nevada

Highlights: Drilling is underway on the Esmeralda County Gold Project, situated within the Walker Lane trend, one of the most prolific gold-producing corridors in North America Sienna's maiden drill program on the project, and the Company's first drill program of 2026 Strong share structure with just over 40 million shares outstanding and strong cash position support multiple expected work programs and marketing initiatives through the second half of 2026 Vancouver, British Columbia--(Newsfile Corp. - September 15, 2026) - Sienna Resources Inc. (TSXV: SIEN) (OTCID: SNNAF) (WKN: A418KR) (the "Company" or "Sienna") is pleased to announce that drilling has commenced on the Company's Esmeralda County Gold Project, located within the prolific Walker Lane trend in Nevada. Titan Drilling Ltd. has mobilized to site and is conducting the Company's maiden drill program on the project. Jason Gigliotti, President of Sienna Resources Inc., stated, "We're excited to have drills turning on the Esmeralda County Gold Project. The Walker Lane trend has a proven track record of hosting significant gold deposits, and this is our first opportunity to test the project with the drill bit. With our tight share structure and intact cash position, we believe any drilling success has the potential for an outsized impact on the Company. We also expect to be active on multiple work programs in the coming weeks giving Sienna multiple opportunities for success. Truly exciting times for Sienna shareholders." To view an enhanced version of this graphic, please visit: https://images.newsfilecorp.com/files/854/314307_5e95726d047bb9c5_002full.jpg About Sienna Sienna has multiple lithium assets in Nevada, which include the 100%-owned, 1,828-acre Elko Lithium Project and the 1,231-acre Cave Creek Lithium Project, both located in Elko County, Nevada, directly bordering and nearly surrounded by Surge Battery Metals' (NILI) Nevada North Lithium Project - the highest-grade lithium clay deposit in the USA. In Clayton Valley, Nevada, Sienna holds the 2,300-acre Deep Basin Lithium Brine JV, which has access to some of the deepest parts of the only lithium brine basin with active production in the USA. Also in Nevada, Sienna holds the 1,156-acre Esmeralda County Gold Project, situated within the Walker Lane trend. In Saskatchewan, Sienna holds the 31,718-acre Stonesthrow Project, prospective for gold, silver, and copper, located directly adjacent to Ramp Metals Inc.'s (RAMP) Rottenstone Project. Qualified Person: The technical contents of this release were reviewed and approved by Frank Bain, PGeo, independent to the Company and a qualified person as defined by National Instrument 43-101. Contact Information Tel: 604-646-6900 www.siennaresourcesinc.com "Jason Gigliotti" President Sienna Resources Inc. 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 release. Forward-Looking Statements This news release contains forward-looking statements and forward-looking information within the meaning of applicable Canadian securities legislation, including statements regarding the commencement and anticipated results of the drill program at the Esmeralda County Gold Project, and the Company's plans and expectations for its work programs in 2026. Forward-looking statements are based on the reasonable assumptions, estimates, analysis and opinions of management made in light of its experience and its perception of trends, current conditions and expected developments, as well as other factors that management believes to be relevant and reasonable in the circumstances at the date such statements are made, but which may prove to be incorrect. Actual results could differ materially from those anticipated due to a number of factors and risks, including risks inherent in mineral exploration. Readers are cautioned not to place undue reliance on forward-looking statements, and the Company disclaims any obligation to update or revise any forward-looking statements, except as required by applicable law. To view the source version of this press release, please visit https://www.newsfilecorp.com/release/314307