# Relationship history for MSHA mine 4604505

Current hierarchy: **Grafton Coal Company → Grafton Coal Company → Corinth Strip Mine**

- 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:** Grafton Coal Company → Corinth Strip Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Grafton Coal Company → Corinth Strip Mine; 1975-03-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Grafton Coal Company → Grafton Coal Company; 1975-03-30 to current/open; source msha-controller-operator-history