# Relationship history for MSHA mine 4404287

Current hierarchy: **Horn Bill E → P B L Coal Company Inc → 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Crumb Jack & Hursel H Justus → No 1; 1950-01-01 to 1978-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Justus Jeffrey → No 1; 1975-08-13 to 1988-12-05; source msha-controller-operator-history
- **operator_operates_mine:** Dean-O Coal Company → No 1; 1976-01-01 to 1976-09-21; source msha-controller-operator-history
- **controller_controls_operator:** Justus Jeffrey → Dean-O Coal Company; 1976-01-01 to 1976-09-21; source msha-controller-operator-history
- **operator_operates_mine:** Bimbo Coal Company Inc → No 1; 1976-09-22 to 1977-10-31; source msha-controller-operator-history
- **controller_controls_operator:** Crumb Jack & Hursel H Justus → Bimbo Coal Company Inc; 1976-09-22 to 1977-10-31; source msha-controller-operator-history
- **operator_operates_mine:** D M C Coal Company Inc → No 1; 1977-11-01 to 1979-02-26; source msha-controller-operator-history
- **controller_controls_mine:** Davies Bill → No 1; 1977-11-01 to 1979-02-26; source msha-controller-operator-history
- **controller_controls_operator:** Davies Bill → D M C Coal Company Inc; 1977-11-01 to 1979-02-26; source msha-controller-operator-history
- **operator_operates_mine:** P B L Coal Company Inc → No 1; 1979-02-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Horn Bill E → No 1; 1979-02-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Horn Bill E → P B L Coal Company Inc; 1979-02-27 to current/open; source msha-controller-operator-history