# Relationship history for MSHA mine 4100288

Current hierarchy: **Boral Limited → Boral Bricks Inc → Marshall Plt & 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 → Marshall Plt & Pits; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Henderson Clay Products Inc → Marshall Plt & Pits; 1950-01-01 to 1985-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Gresham L C Jr → Marshall Plt & Pits; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gresham L C Jr → Henderson Clay Products Inc; 1950-01-01 to 1985-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Boral Bricks Inc → Marshall Plt & Pits; 1985-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Boral Limited → Boral Bricks Inc; 1985-07-01 to current/open; source msha-controller-operator-history