# Relationship history for MSHA mine 4002673

Current hierarchy: **Tipton County → Tipton County Public Works → Franklin Gravel 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Tipton County Public Works → Franklin Gravel Pit; 1980-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Tipton County → Franklin Gravel Pit; 1980-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tipton County → Tipton County Public Works; 1980-11-01 to current/open; source msha-controller-operator-history