# Relationship history for MSHA mine 2300041

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Corp → West Bethany 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:** Martin Marietta Materials Inc → West Bethany Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Raid Quarries Division → West Bethany Quarry; 1950-01-01 to 1978-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Medusa Corp → West Bethany Quarry; 1950-01-01 to 1979-04-05; source msha-controller-operator-history
- **controller_controls_operator:** Medusa Corp → Raid Quarries Division; 1950-01-01 to 1978-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Crane Company → West Bethany Quarry; 1978-12-13 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Medusa Aggregates Company → West Bethany Quarry; 1979-01-01 to 1979-06-10; source msha-controller-operator-history
- **controller_controls_operator:** Crane Company → Medusa Aggregates Company; 1979-01-01 to 1979-06-10; source msha-controller-operator-history
- **operator_operates_mine:** Hardrock Quarries Inc → West Bethany Quarry; 1979-06-11 to 1982-10-06; source msha-controller-operator-history
- **controller_controls_mine:** Howard L  Miller → West Bethany Quarry; 1979-06-11 to 1982-10-06; source msha-controller-operator-history
- **controller_controls_operator:** Howard L  Miller → Hardrock Quarries Inc; 1979-06-11 to 1982-10-06; source msha-controller-operator-history
- **operator_operates_mine:** Hardrock Quarries-Milburn Of St Joseph → West Bethany Quarry; 1982-10-07 to 1984-01-22; source msha-controller-operator-history
- **controller_controls_mine:** James  Burnham → West Bethany Quarry; 1982-10-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James  Burnham → Hardrock Quarries-Milburn Of St Joseph; 1982-10-07 to 1984-01-22; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Corp → West Bethany Quarry; 1984-01-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Corp; 1984-01-23 to current/open; source msha-controller-operator-history