# Relationship history for MSHA mine 4002494

Current hierarchy: **Gibson Herbert & Roy Coleman → Debco Coal Company Inc → No 1 Tipple**

- 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:** Champion International Corporation → No 1 Tipple; 1976-08-05 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Debco Coal Company Inc → No 1 Tipple; 1979-03-01 to 1980-09-15; source msha-controller-operator-history
- **controller_controls_operator:** Champion International Corporation → Debco Coal Company Inc; 1979-03-01 to 1980-09-15; source msha-controller-operator-history
- **operator_operates_mine:** Debco Coal Company Inc → No 1 Tipple; 1980-09-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gibson Herbert & Roy Coleman → No 1 Tipple; 1980-09-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gibson Herbert & Roy Coleman → Debco Coal Company Inc; 1980-09-16 to current/open; source msha-controller-operator-history