 Anderson Steel Supply INC | Great Falls | 20–99 | ● ACTIVE |
| RARec Advanced Silicon Materials LLC | Butte | 100–499 | ● ACTIVE |
 United States Antimony Corporation | Thompson Falls | — | ● ACTIVE |
| MPMontana Precision Products LLC | Butte | 100–499 | ◐ LIKELY ACTIVE |
 Currier Certified Welding, INC. | Kalispell | — | ◐ LIKELY ACTIVE |
| SMStillwater Mining Company Base Metals Refinery | Columbus | 20–99 | ◐ LIKELY ACTIVE |
| CMContact Mining CO | Philipsburg | — | ◐ LIKELY ACTIVE |
| SMStillwater Mining CO Smelter | Columbus | — | ◐ LIKELY ACTIVE |
| AIAffco INC | Anaconda | — | ◇ UNVERIFIED |
| AAsarco | Helena | — | ◇ UNVERIFIED |
| BIBest in Bronze INC | Kalispell | — | ◇ UNVERIFIED |
| CIChovanak INC | Helena | — | ◇ UNVERIFIED |
| CFColumbia Falls Aluminum | Columbia Falls | — | ◇ UNVERIFIED |
| CFColumbia Falls Aluminum Company Building 1 | Columbia Falls | — | ◇ UNVERIFIED |
| NANorthwest Art Casting INC | Bozeman | — | ◇ UNVERIFIED |
| SPSmc Precious Metals Smelter & Base Metal Refy | Columbus | — | ◇ UNVERIFIED |
 Truenorth Steel | Billings | — | ◇ UNVERIFIED |
| UAUS Antimony CORP | Thompson Falls | — | ◇ UNVERIFIED |
| BIBowman Industries LLC | Belgrade | — | ◐ LIKELY ACTIVE |
| SMStillwater Mining Company Base Metals Smelter | Columbus | 20–99 | ◐ LIKELY ACTIVE |
| ACArt Casting of Montana, INC. | Belgrade | — | ◇ UNVERIFIED |
| ABAti Bozeman INC | Bozeman | — | ◇ UNVERIFIED |
| CIClark Industrial INC. | Missoula | — | ◇ UNVERIFIED |
| CPColumbus Processing Facility | Columbus | — | ◇ UNVERIFIED |
| CMContact Mining Company | Philipsburg | — | ◇ UNVERIFIED |
| CSContinental Steel Works, INC. | Butte | — | ◇ UNVERIFIED |
| CICustom Ii Metal Fabrication and Welding | Bozeman | — | ◇ UNVERIFIED |
| JIJms INC. | Bozeman | — | ◇ UNVERIFIED |
| JMJohnson Metal Works LLC | Bozeman | — | ◇ UNVERIFIED |
| KHKozba Holdings LLC | Billings | — | ◇ UNVERIFIED |
| NSNorthwest Short Line, LLC | Hamilton | — | ◇ UNVERIFIED |
| SMStillwater Mining Company | Columbus | — | ◇ UNVERIFIED |
| SMStillwater Mining CO Smelter | Columbus | — | ◇ UNVERIFIED |
| UAUS Antimony CORP | Thompson Falls | — | ◇ UNVERIFIED |
