# Relationship history for MSHA mine 4002840

Current hierarchy: **Thomas Virgil C → Thomas Coal Company Inc → Tccc No 45**

- 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:** Massey Energy Company → Tccc No 45; 1976-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Grundy Mining Company Inc → Tccc No 45; 1983-09-01 to 1983-12-18; source msha-controller-operator-history
- **controller_controls_operator:** Massey Energy Company → Grundy Mining Company Inc; 1983-09-01 to 1983-12-18; source msha-controller-operator-history
- **operator_operates_mine:** Thomas Coal Company Inc → Tccc No 45; 1983-12-19 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Thomas Virgil C Et Al → Tccc No 45; 1983-12-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas Virgil C Et Al → Thomas Coal Company Inc; 1983-12-19 to current/open; source msha-controller-operator-history