# Relationship history for MSHA mine 4100937

Current hierarchy: **Asbury Advanced Materials → Southwestern Graphite Company → DIXON/SOUTHWESTERN GRAPHITE CO.**

- 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:** Southwestern Graphite Company → DIXON/SOUTHWESTERN GRAPHITE CO.; 1950-01-01 to 1999-03-02; source msha-controller-operator-history
- **controller_controls_mine:** Gino N  Pala → DIXON/SOUTHWESTERN GRAPHITE CO.; 1950-01-01 to 1999-03-02; source msha-controller-operator-history
- **controller_controls_operator:** Gino N  Pala → Southwestern Graphite Company; 1950-01-01 to 1999-03-02; source msha-controller-operator-history
- **controller_controls_mine:** Asbury Advanced Materials → DIXON/SOUTHWESTERN GRAPHITE CO.; 1993-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Southwestern Graphite Company → DIXON/SOUTHWESTERN GRAPHITE CO.; 1999-03-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Asbury Advanced Materials → Southwestern Graphite Company; 1999-03-03 to current/open; source msha-controller-operator-history