# Relationship history for MSHA mine 0203408

Current hierarchy: **Norman M  Montgomery → Gila Rock Products → Plant # 1**

- 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:** Cheryl  Montgomery  et al → Plant # 1; 2002-04-17 to 2019-01-21; source msha-controller-operator-history
- **operator_operates_mine:** Gila Rock Products → Plant # 1; 2019-01-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cheryl  Montgomery  et al → Gila Rock Products; 2019-01-22 to 2019-01-21; source msha-controller-operator-history
- **controller_controls_operator:** Norman  Montgomery  et al → Gila Rock Products; 2019-01-22 to 2019-01-21; source msha-controller-operator-history
- **controller_controls_mine:** Norman M  Montgomery → Plant # 1; 2019-01-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Norman M  Montgomery → Gila Rock Products; 2019-01-22 to current/open; source msha-controller-operator-history