# Relationship history for MSHA mine 1201398

Current hierarchy: **Heidelberg Materials AG → Hanson Aggregates Midwest Inc → Washington County 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

- **controller_controls_mine:** Koppers Company Inc → Washington County Plant; 1950-01-01 to 1988-11-13; source msha-controller-operator-history
- **operator_operates_mine:** Owsley Limestone Company → Washington County Plant; 1980-09-01 to 1987-06-07; source msha-controller-operator-history
- **controller_controls_mine:** Owsley Bill & J D Et Al → Washington County Plant; 1980-09-01 to 1987-06-07; source msha-controller-operator-history
- **controller_controls_operator:** Owsley Bill & J D Et Al → Owsley Limestone Company; 1980-09-01 to 1987-06-07; source msha-controller-operator-history
- **operator_operates_mine:** Kentucky Stone Company → Washington County Plant; 1987-06-08 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_operator:** Koppers Company Inc → Kentucky Stone Company; 1987-06-08 to 1988-11-13; source msha-controller-operator-history
- **operator_operates_mine:** Hanson Aggregates Midwest Inc → Washington County Plant; 1988-11-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Washington County Plant; 1988-11-14 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Hanson Aggregates Midwest Inc; 1988-11-14 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Washington County Plant; 2007-08-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Hanson Aggregates Midwest Inc; 2007-08-23 to current/open; source msha-controller-operator-history