# Relationship history for MSHA mine 4404668

Current hierarchy: **M A Hanna Company; W R Grace Company → Rapoca Energy Company → Banner Tipple No 1 & 2**

- 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:** Fields Resources Inc → Banner Tipple No 1 & 2; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Norton Coal Company → Banner Tipple No 1 & 2; 1977-06-01 to 1983-05-01; source msha-controller-operator-history
- **controller_controls_operator:** Fields Resources Inc → Norton Coal Company; 1977-06-01 to 1983-05-01; source msha-controller-operator-history
- **controller_controls_mine:** M A Hanna Company et al → Banner Tipple No 1 & 2; 1980-06-26 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Rapoca Energy Company → Banner Tipple No 1 & 2; 1983-05-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** M A Hanna Company et al → Rapoca Energy Company; 1983-05-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** W R Grace Company et al → Rapoca Energy Company; 1983-05-02 to current/open; source msha-controller-operator-history