# Relationship history for MSHA mine 4405951

Current hierarchy: **Ernest E  Varney → Black Widow Coal Company Inc → Mine #4**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Ernest E  Varney et al → Mine #4; 1976-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mullins Rosbal → Mine #4; 1978-11-27 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Tazco Inc → Mine #4; 1982-10-01 to 1986-02-02; source msha-controller-operator-history
- **controller_controls_operator:** Mullins Rosbal → Tazco Inc; 1982-10-01 to 1986-02-02; source msha-controller-operator-history
- **operator_operates_mine:** Black Widow Coal Company Inc → Mine #4; 1986-02-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ernest E  Varney et al → Black Widow Coal Company Inc; 1986-02-03 to current/open; source msha-controller-operator-history