# Relationship history for MSHA mine 0300261

Current hierarchy: **US Vanadium Holding Company, LLC → US Vanadium - Benton, LLC → U.S. Vanadium - Benton, LLC**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** American Cyanamid Company → U.S. Vanadium - Benton, LLC; 1950-01-01 to 1989-11-22; source msha-controller-operator-history
- **controller_controls_mine:** American Cyanamid Company → U.S. Vanadium - Benton, LLC; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** American Cyanamid Company → American Cyanamid Company; 1950-01-01 to 1989-11-22; source msha-controller-operator-history
- **controller_controls_mine:** Alcoa Inc & Norton Company → U.S. Vanadium - Benton, LLC; 1986-04-01 to 2001-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Can-Am Absorbents Company Inc → U.S. Vanadium - Benton, LLC; 1989-11-23 to 1996-03-28; source msha-controller-operator-history
- **controller_controls_mine:** Robert J  Leonard Jr → U.S. Vanadium - Benton, LLC; 1989-11-23 to 1996-03-28; source msha-controller-operator-history
- **controller_controls_operator:** Robert J  Leonard Jr → Can-Am Absorbents Company Inc; 1989-11-23 to 1996-03-28; source msha-controller-operator-history
- **operator_operates_mine:** Saint-Gobain Proppants → U.S. Vanadium - Benton, LLC; 1996-03-29 to 2021-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Alcoa Inc & Norton Company → Saint-Gobain Proppants; 1996-03-29 to 2001-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Saint-Gobain → U.S. Vanadium - Benton, LLC; 2001-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Saint-Gobain → Saint-Gobain Proppants; 2001-04-01 to 2021-07-31; source msha-controller-operator-history
- **operator_operates_mine:** US Vanadium - Benton, LLC → U.S. Vanadium - Benton, LLC; 2021-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** US Vanadium Holding Company, LLC → U.S. Vanadium - Benton, LLC; 2021-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** US Vanadium Holding Company, LLC → US Vanadium - Benton, LLC; 2021-08-01 to current/open; source msha-controller-operator-history