# Relationship history for MSHA mine 4103162

Current hierarchy: **General Dynamics Corp → El Paso Sand Products Inc → Chadwick Pit**

- 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:** General Dynamics Corp → Chadwick Pit; 1983-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Southwest Road & Paving Company Inc → Chadwick Pit; 1983-03-01 to 1984-09-12; source msha-controller-operator-history
- **controller_controls_mine:** Chadwick-Williams → Chadwick Pit; 1983-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chadwick-Williams → Southwest Road & Paving Company Inc; 1983-03-01 to 1984-09-12; source msha-controller-operator-history
- **operator_operates_mine:** El Paso Sand Products Inc → Chadwick Pit; 1984-09-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** General Dynamics Corp → El Paso Sand Products Inc; 1984-09-13 to current/open; source msha-controller-operator-history