# Relationship history for MSHA mine 3302011

Current hierarchy: **Ernst Aggregates Inc → Bellbrook Gravel → Bellbrook Gravel**

- 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

- **operator_operates_mine:** Bellbrook Gravel Inc → Bellbrook Gravel; 1950-01-01 to 1986-09-17; source msha-controller-operator-history
- **controller_controls_mine:** Callison P T → Bellbrook Gravel; 1950-01-01 to 1986-09-17; source msha-controller-operator-history
- **controller_controls_operator:** Callison P T → Bellbrook Gravel Inc; 1950-01-01 to 1986-09-17; source msha-controller-operator-history
- **operator_operates_mine:** Bellbrook Gravel → Bellbrook Gravel; 1986-09-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ernst Aggregates Inc → Bellbrook Gravel; 1986-09-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ernst Aggregates Inc → Bellbrook Gravel; 1986-09-18 to current/open; source msha-controller-operator-history