# Relationship history for MSHA mine 4002406

Current hierarchy: **Gibson Herbert & Roy Coleman → Valley Resources → 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Royal Blue Coal Company → No 1 Tipple; 1978-05-01 to 1979-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Conley D C → No 1 Tipple; 1978-05-01 to 1979-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Conley D C → Royal Blue Coal Company; 1978-05-01 to 1979-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Royal Blue Coal Company → No 1 Tipple; 1979-03-01 to 1981-03-25; source msha-controller-operator-history
- **controller_controls_mine:** Davis Jerry W & Linda R Jerrolds → No 1 Tipple; 1979-03-01 to 1981-03-25; source msha-controller-operator-history
- **controller_controls_operator:** Davis Jerry W & Linda R Jerrolds → Royal Blue Coal Company; 1979-03-01 to 1981-03-25; source msha-controller-operator-history
- **operator_operates_mine:** Valley Resources → No 1 Tipple; 1981-03-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gibson Herbert & Roy Coleman → No 1 Tipple; 1981-03-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gibson Herbert & Roy Coleman → Valley Resources; 1981-03-26 to current/open; source msha-controller-operator-history