# Relationship history for MSHA mine 4202753

Current hierarchy: **Brian  Nichols; Trudi  Nichols → Iron Mtn Rock Products → Smith 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

- **operator_operates_mine:** Iron Mtn Rock Products → Smith Pit; 2023-08-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Brian  Nichols et al → Smith Pit; 2023-08-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brian  Nichols et al → Iron Mtn Rock Products; 2023-08-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Trudi  Nichols et al → Iron Mtn Rock Products; 2023-08-02 to current/open; source msha-controller-operator-history