- AMCOL International Corp
- American Colloid Co
- American Colloid Co
- Bentonite Corp
- Black Hills Bentonite Co
- Black Hills Bentonite Co
- BPM Minerals
- Bpm Minerals LLC
- Carco Mineral Resources Inc
- Central Oregon Bentonite Co
- Engelhard Corp
- Evergreen Bentonite Inc
- First Bentonite
- Montana Bentonite
- Rennecker Limited Inc
- Southern Colorado Bentonite Co
- Teague Mineral Products
- Wyo-Ben Inc
- Wyo-Ben Inc
- Wyo-Ben Inc
