# Relationship history for MSHA mine 3800768

Current hierarchy: **Ferroglobe PLC → Ferroglobe USA Quartz, Inc. → Marlboro Mine**

- 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:** Orkla A S A → Marlboro Mine; 2005-03-28 to 2007-02-20; source msha-controller-operator-history
- **controller_controls_mine:** Globe Metallurgical Inc → Marlboro Mine; 2007-02-21 to 2011-07-31; source msha-controller-operator-history
- **controller_controls_mine:** Ferroglobe PLC → Marlboro Mine; 2011-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ferroglobe USA Quartz, Inc. → Marlboro Mine; 2024-02-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Orkla A S A → Ferroglobe USA Quartz, Inc.; 2024-02-22 to 2007-02-20; source msha-controller-operator-history
- **controller_controls_operator:** Globe Metallurgical Inc → Ferroglobe USA Quartz, Inc.; 2024-02-22 to 2011-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Ferroglobe PLC → Ferroglobe USA Quartz, Inc.; 2024-02-22 to current/open; source msha-controller-operator-history