# Relationship history for MSHA mine 1505027

Current hierarchy: **Massey Energy Company → T C H Coal Company Inc → No 1 Surface 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

- **operator_operates_mine:** T C H Coal Co Inc → No 1 Surface Mine; 1950-01-01 to 1976-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Travis  Bush et al → No 1 Surface Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Travis  Bush et al → T C H Coal Co Inc; 1950-01-01 to 1976-03-31; source msha-controller-operator-history
- **operator_operates_mine:** T C H Coal Company Inc → No 1 Surface Mine; 1976-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Massey Energy Company → No 1 Surface Mine; 1976-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Massey Energy Company → T C H Coal Company Inc; 1976-04-01 to current/open; source msha-controller-operator-history