# Relationship history for MSHA mine 4605154

Current hierarchy: **Powell Herman → Ibex Coal Company → No 1**

- 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:** B & F Coal Company → No 1; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** B & F Coal Company → No 1; 1976-05-07 to 1978-06-18; source msha-controller-operator-history
- **controller_controls_operator:** B & F Coal Company → B & F Coal Company; 1976-05-07 to 1978-06-18; source msha-controller-operator-history
- **operator_operates_mine:** B & F Coal Company → No 1; 1978-06-19 to 1981-06-01; source msha-controller-operator-history
- **controller_controls_mine:** Lambert Jerry → No 1; 1978-06-19 to 1981-06-01; source msha-controller-operator-history
- **controller_controls_operator:** Lambert Jerry → B & F Coal Company; 1978-06-19 to 1981-06-01; source msha-controller-operator-history
- **operator_operates_mine:** Ibex Coal Company → No 1; 1981-06-02 to 1987-05-13; source msha-controller-operator-history
- **controller_controls_mine:** William  Smith et al → No 1; 1981-06-02 to 1987-05-13; source msha-controller-operator-history
- **controller_controls_operator:** William  Smith et al → Ibex Coal Company; 1981-06-02 to 1987-05-13; source msha-controller-operator-history
- **operator_operates_mine:** Ibex Coal Company → No 1; 1987-05-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Powell Herman → No 1; 1987-05-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Powell Herman → Ibex Coal Company; 1987-05-14 to current/open; source msha-controller-operator-history