# Relationship history for MSHA mine 1600916

Current hierarchy: **Bohannon O L → Bohannon Sand & Dirt → BOHANNON SAND & DIRT**

- 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:** Valney Cosby → BOHANNON SAND & DIRT; 1950-01-01 to 1983-12-11; source msha-controller-operator-history
- **controller_controls_mine:** Cosby Valney → BOHANNON SAND & DIRT; 1950-01-01 to 1983-12-11; source msha-controller-operator-history
- **controller_controls_operator:** Cosby Valney → Valney Cosby; 1950-01-01 to 1983-12-11; source msha-controller-operator-history
- **operator_operates_mine:** Bohannon Sand & Dirt → BOHANNON SAND & DIRT; 1983-12-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bohannon O L → BOHANNON SAND & DIRT; 1983-12-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bohannon O L → Bohannon Sand & Dirt; 1983-12-12 to current/open; source msha-controller-operator-history