# Relationship history for MSHA mine 3303848

Current hierarchy: **Olen Corporation → The Olen Corporation → Fredericktown Plant**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Kokosing Materials Inc → Fredericktown Plant; 1980-11-01 to 1987-09-22; source msha-controller-operator-history
- **controller_controls_mine:** Kokosing Const Co Inc Et Al → Fredericktown Plant; 1980-11-01 to 1987-09-22; source msha-controller-operator-history
- **controller_controls_operator:** Kokosing Const Co Inc Et Al → Kokosing Materials Inc; 1980-11-01 to 1987-09-22; source msha-controller-operator-history
- **controller_controls_mine:** Olen Corporation → Fredericktown Plant; 1983-05-31 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** The Olen Corporation → Fredericktown Plant; 1987-09-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Olen Corporation → The Olen Corporation; 1987-09-23 to current/open; source msha-controller-operator-history