Critical mineral mining company opens second Montana operation in Radersburg

The road to the United States’ quest to secure a domestic supply of the critical mineral antimony runs through Radersburg.

Gov. Greg Gianforte joined officials from United States Antimony Corporation for a “rock-breaking” ceremony at a newly upgraded mill and lab the mining company recently started operating in Broadwater County.

“Radersburg was our missing link,” said Gary C. Evans, chief executive officer of USAC. “And now we can proudly beat our chest and say we are a fully integrated antimony mining company, the only one in the world outside of Russia and China.”

After acquiring the facility in January, USAC spent around $1 million to upgrade the facility to analyze and concentrate the raw antimony ore mined from the company’s operations in Alaska and Thompson Falls, where the company celebrated the groundbreaking of a new expansion in September 2025.

The facility will take the mined antimony from low grade to high grade, which is then made into 50 pound ingots at the Thompson Falls facility.

All this is to fulfill a $245 million contract through the Defense Logistics Agency to supply the Department of War with antimony.

“That's why today is about more than opening a new facility, it's about strengthening Montana's economy, creating good paying jobs at home, and continuing to secure America's future,” Gianforte said. “For too long, our nation has relied on our adversaries for these critical minerals that power our economy and support national defense. That dependence has left America vulnerable.”

Since World War II, antimony has been a key material in the U.S. production of military ammunitions, according to the U.S International Trade Commission’s 2021 report.

“As of 2020, the leading uses of antimony in the United States were in flame retardants, lead-acid batteries, as a key alloying material for strength (e.g., shielding materials), and antifriction alloys,” the report reads. “Additionally, antimony is used in a variety of military applications, including night vision goggles, explosive formulations, flares, nuclear weapons production, and infrared sensors.”

The world’s largest supplier of antimony, China, announced it would halt export of the critical mineral to the U.S in response to limits imposed by Washington on semiconductor-related export, the Associated Press reported in December 2024.