# Relationship history for MSHA mine 1600484

Current hierarchy: **Aubry L  Barber III; Lionel H  Barber → Acme Gravel Company Inc → Acme Dredge & Plant Or Acme Dredge & Pla**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Acme Gravel Company Inc → Acme Dredge & Plant Or Acme Dredge & Pla; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Aubry L  Barber III  et al → Acme Dredge & Plant Or Acme Dredge & Pla; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Aubry L  Barber III  et al → Acme Gravel Company Inc; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lionel H  Barber  et al → Acme Gravel Company Inc; 1950-01-01 to current/open; source msha-controller-operator-history