# Relationship history for MSHA mine 1101922

Current hierarchy: **Atochem North America Inc → Ozark-Mahoning Company → ROSICLARE MILL**

- 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:** Ozark-Mahoning Company → ROSICLARE MILL; 1950-01-01 to 1991-01-08; source msha-controller-operator-history
- **controller_controls_mine:** Pennwalt Corp → ROSICLARE MILL; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pennwalt Corp → Ozark-Mahoning Company; 1950-01-01 to 1991-01-08; source msha-controller-operator-history
- **operator_operates_mine:** Ozark-Mahoning Company → ROSICLARE MILL; 1991-01-09 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Atochem North America Inc → ROSICLARE MILL; 1991-01-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Atochem North America Inc → Ozark-Mahoning Company; 1991-01-09 to current/open; source msha-controller-operator-history