# Relationship history for MSHA mine 1512855

Current hierarchy: **Partin Lester Hugh → Bronco Coal Company Inc → Bronco #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:** Partin Wayland Jr → Bronco #1; 1980-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** B & W Coal Company → Bronco #1; 1981-05-01 to 1988-12-28; source msha-controller-operator-history
- **controller_controls_operator:** Partin Wayland Jr → B & W Coal Company; 1981-05-01 to 1988-12-28; source msha-controller-operator-history
- **operator_operates_mine:** Bronco Coal Company Inc → Bronco #1; 1988-12-29 to 1990-05-02; source msha-controller-operator-history
- **controller_controls_mine:** Partin Wayland Et Al → Bronco #1; 1988-12-29 to 1990-05-02; source msha-controller-operator-history
- **controller_controls_operator:** Partin Wayland Et Al → Bronco Coal Company Inc; 1988-12-29 to 1990-05-02; source msha-controller-operator-history
- **operator_operates_mine:** Bronco Coal Company Inc → Bronco #1; 1990-05-03 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Partin Lester Hugh → Bronco #1; 1990-05-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Partin Lester Hugh → Bronco Coal Company Inc; 1990-05-03 to current/open; source msha-controller-operator-history