American Tungsten & Antimony Reports High-Grade Antimony Discovery in Utah, Highlighting Potential for Major U.S. Critical Minerals Deposit

NEW YORK, March 11, 2026 /PRNewswire/ -- American Tungsten & Antimony Ltd. (ASX: AT4; OTCQB: ATALF) today reported high-grade antimony results from its first drill holes at the Little Emma Prospect within the Company's 100%-owned Antimony Canyon Project in Utah, marking a strong start to its maiden drilling program and reinforcing the potential for a large-scale antimony system in the United States.

The initial drilling program intersected shallow, high-grade stibnite mineralization, providing early confirmation of the Company's geological model and demonstrating encouraging continuity within the mineralized system.

Key intercepts include:

• 11.03m @ 3.1% Sb from 25.91m, including 2.62m @ 12.54% Sb from 29.2m
• 8.47m @ 2.67% Sb from 31.15m, including 2.2m @ 9.69% Sb from 36.88m
• 2.14m @ 3.02% Sb from 40.23m

The Little Emma Prospect is one of more than 20 historic antimony mines located within AT4's patented claim block at Antimony Canyon, highlighting the district-scale exploration potential across the property.

These results follow the Company's ASX announcement dated 10 March 2026, which outlined the encouraging results from the initial drilling campaign.

Additional details can be found here:
https://cdn-api.markitdigital.com/apiman-gateway/ASX/asx-research/1.0/file/2924-03066387-6A1315549

Exceptional Grades in a Strategic U.S. Critical Mineral

"Intersecting mineralization in four of our first seven holes is an exceptional start at Antimony Canyon," said Andre Booyzen, Managing Director of American Tungsten & Antimony.

"Outstanding grades of up to 66.47% Sb highlight the strength of the system. These results compare very favorably with grades reported from major North American antimony deposits such as the Stibnite Gold Project in Idaho, currently being advanced by Perpetua Resources."

Mr. Booyzen noted that the scale of alteration and mineralization already observed indicates the potential for a large hydrothermal system capable of hosting a significant antimony resource.

"Many of the world's largest antimony deposits are located in China and were developed within similar hydrothermal systems. The mineralization we are seeing at Antimony Canyon shows characteristics consistent with those large Chinese deposits," explained Booyzen.

"With extensive sulphidation and large anomalous zones already identified, we believe Antimony Canyon has the potential to emerge as a major new antimony district in the United States, and potentially one of the largest antimony deposits discovered domestically," he said

Strategic Timing as U.S. Seeks Secure Antimony Supply

Antimony is classified by the U.S. Government as a critical mineral essential for national security, with applications in defense systems, semiconductors, batteries, flame retardants and advanced manufacturing.

The United States currently relies heavily on foreign sources for antimony supply, with China historically dominating global production.

The emergence of a significant domestic antimony resource would represent an important development for U.S. supply chain security.

Expanding U.S. Critical Minerals Portfolio

American Tungsten & Antimony is focused on re-establishing domestic supply of antimony and tungsten, two minerals essential to defense and industrial supply chains.

In addition to the Antimony Canyon Project in Utah, the Company is advancing a growing portfolio of U.S. projects including:

• Tennessee Mountain Tungsten Project – Nevada
• Sage Hen Tungsten Project – Nevada
• Nightingale Tungsten Project – Nevada
• Dutch Mountain Tungsten Project – Utah

Together these projects position AT4 as an emerging developer of strategically important critical minerals in the United States, supporting the growing need for secure domestic supply chains.

SOURCE American Tungsten and Antimony