# Relationship history for MSHA mine 1200005

Current hierarchy: **Heidelberg Materials AG → Hanson Material Service → Babcock Quarry**

- 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:** General Dynamics Corp → Babcock Quarry; 1950-01-01 to 2006-06-15; source msha-controller-operator-history
- **operator_operates_mine:** W C Babcock Construction Company Inc → Babcock Quarry; 1950-01-01 to 1997-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Roger E  Ward → Babcock Quarry; 1950-01-01 to 1997-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Roger E  Ward → W C Babcock Construction Company Inc; 1950-01-01 to 1997-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Babcock Stone Inc → Babcock Quarry; 1997-06-01 to 1999-03-14; source msha-controller-operator-history
- **controller_controls_mine:** Dale E  Ward → Babcock Quarry; 1997-06-01 to 1999-03-14; source msha-controller-operator-history
- **controller_controls_operator:** Dale E  Ward → Babcock Stone Inc; 1997-06-01 to 1999-03-14; source msha-controller-operator-history
- **operator_operates_mine:** Hanson Material Service → Babcock Quarry; 1999-03-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** General Dynamics Corp → Hanson Material Service; 1999-03-15 to 2006-06-15; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Babcock Quarry; 2006-06-16 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Hanson Material Service; 2006-06-16 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Babcock Quarry; 2007-08-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Hanson Material Service; 2007-08-23 to current/open; source msha-controller-operator-history