# Relationship history for MSHA mine 0301587

Current hierarchy: **Martin Marietta Materials Inc → Hanson Aggregates → DELIGHT 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Hanson PLC → DELIGHT PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Frank B  Treat Jr → DELIGHT PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Tri-State Concrete Company Inc → DELIGHT PLANT; 1984-11-01 to 1987-05-10; source msha-controller-operator-history
- **controller_controls_operator:** Frank B  Treat Jr → Tri-State Concrete Company Inc; 1984-11-01 to 1987-05-10; source msha-controller-operator-history
- **operator_operates_mine:** Tri-State Sand & Gravel Inc → DELIGHT PLANT; 1987-05-11 to 1987-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Edward  Kennon → DELIGHT PLANT; 1987-05-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edward  Kennon → Tri-State Sand & Gravel Inc; 1987-05-11 to 1987-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Hanson Aggregates West Inc → DELIGHT PLANT; 1988-01-01 to 2004-08-24; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Hanson Aggregates West Inc; 1988-01-01 to 2004-08-24; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → DELIGHT PLANT; 1988-11-14 to 2007-08-22; source msha-controller-operator-history
- **operator_operates_mine:** Hanson Aggregates → DELIGHT PLANT; 2004-08-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Hanson Aggregates; 2004-08-25 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → DELIGHT PLANT; 2007-08-23 to 2021-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Hanson Aggregates; 2007-08-23 to 2021-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → DELIGHT PLANT; 2021-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Hanson Aggregates; 2021-10-01 to current/open; source msha-controller-operator-history