# Relationship history for MSHA mine 3400374

Current hierarchy: **Hanson PLC → Mc Michael Concrete Company → Jenks 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:** Mc Michael Concrete Company → Jenks Plant; 1950-01-01 to 1979-12-14; source msha-controller-operator-history
- **controller_controls_mine:** Mc Michael Company → Jenks Plant; 1950-01-01 to 1979-12-14; source msha-controller-operator-history
- **controller_controls_operator:** Mc Michael Company → Mc Michael Concrete Company; 1950-01-01 to 1979-12-14; source msha-controller-operator-history
- **operator_operates_mine:** Mc Michael Concrete Company → Jenks Plant; 1979-12-15 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_mine:** Koppers Company Inc → Jenks Plant; 1979-12-15 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_operator:** Koppers Company Inc → Mc Michael Concrete Company; 1979-12-15 to 1988-11-13; source msha-controller-operator-history
- **operator_operates_mine:** Mc Michael Concrete Company → Jenks Plant; 1988-11-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Jenks Plant; 1988-11-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Mc Michael Concrete Company; 1988-11-14 to current/open; source msha-controller-operator-history