# Relationship history for MSHA mine 4002719

Current hierarchy: **Decatur County-Tn → Decatur County Highway Department → Gibson Pit**

- 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:** John H  Ford  et al → Gibson Pit; 1980-05-27 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Camden Gravel Company → Gibson Pit; 1981-04-01 to 1985-02-10; source msha-controller-operator-history
- **controller_controls_operator:** John H  Ford  et al → Camden Gravel Company; 1981-04-01 to 1985-02-10; source msha-controller-operator-history
- **operator_operates_mine:** Decatur County Highway Department → Gibson Pit; 1985-02-11 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Decatur County-Tn → Gibson Pit; 1985-02-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Decatur County-Tn → Decatur County Highway Department; 1985-02-11 to current/open; source msha-controller-operator-history