# Relationship history for MSHA mine 1511612

Current hierarchy: **Hobart  Anderson → Broken Hill Mining Company Inc → No 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Curtis  Francis → No 4; 1971-11-06 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Big Hill Coal Company → No 4; 1978-10-01 to 1989-10-29; source msha-controller-operator-history
- **controller_controls_operator:** Curtis  Francis → Big Hill Coal Company; 1978-10-01 to 1989-10-29; source msha-controller-operator-history
- **controller_controls_mine:** Hobart  Anderson  et al → No 4; 1986-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** J B & R Coal Company Inc → No 4; 1989-10-30 to 1992-06-25; source msha-controller-operator-history
- **controller_controls_mine:** Cable Robert → No 4; 1989-10-30 to 1992-06-25; source msha-controller-operator-history
- **controller_controls_operator:** Cable Robert → J B & R Coal Company Inc; 1989-10-30 to 1992-06-25; source msha-controller-operator-history
- **controller_controls_mine:** Phillips Billy Joe → No 4; 1991-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** B J Coal Company Inc → No 4; 1992-06-26 to 1994-07-21; source msha-controller-operator-history
- **controller_controls_operator:** Phillips Billy Joe → B J Coal Company Inc; 1992-06-26 to 1994-07-21; source msha-controller-operator-history
- **operator_operates_mine:** Broken Hill Mining Company Inc → No 4; 1994-07-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hobart  Anderson  et al → Broken Hill Mining Company Inc; 1994-07-22 to current/open; source msha-controller-operator-history