# Relationship history for MSHA mine 0403821

Current hierarchy: **RRM Development Corporation; Mitsubishi Corp → Robertson'S Ready Mix Ltd → AZUSA**

- 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:** Owl Rock Products → AZUSA; 1950-01-01 to 1995-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Mitsubishi Corp → AZUSA; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mitsubishi Corp → Owl Rock Products; 1950-01-01 to 1995-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Robertson'S Ready Mix Ltd → AZUSA; 1995-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** RRM Development Corporation et al → AZUSA; 1995-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** RRM Development Corporation et al → Robertson'S Ready Mix Ltd; 1995-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mitsubishi Corp  et al → Robertson'S Ready Mix Ltd; 1995-10-01 to current/open; source msha-controller-operator-history