# Relationship history for MSHA mine 2200023

Current hierarchy: **Boral Limited → Boral Bricks Inc → MACON PLANT & PITS**

- 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

- **controller_controls_mine:** Boral Limited → MACON PLANT & PITS; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Delta Macon Brick & Tile Company Inc → MACON PLANT & PITS; 1950-01-01 to 1987-10-21; source msha-controller-operator-history
- **controller_controls_mine:** Delta Brick & Tile Company Inc → MACON PLANT & PITS; 1950-01-01 to 1987-10-21; source msha-controller-operator-history
- **controller_controls_operator:** Delta Brick & Tile Company Inc → Delta Macon Brick & Tile Company Inc; 1950-01-01 to 1987-10-21; source msha-controller-operator-history
- **operator_operates_mine:** Boral Bricks Inc → MACON PLANT & PITS; 1987-10-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Boral Limited → Boral Bricks Inc; 1987-10-22 to current/open; source msha-controller-operator-history