# Relationship history for MSHA mine 1202378

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials, Inc → Perkinsville 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:** Martin Marietta Materials Inc → Perkinsville Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** The Heritage Group → Perkinsville Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** US Aggregates Inc → Perkinsville Plant; 2005-10-19 to 2023-04-16; source msha-controller-operator-history
- **controller_controls_operator:** The Heritage Group → US Aggregates Inc; 2005-10-19 to 2023-04-16; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials, Inc → Perkinsville Plant; 2023-04-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials, Inc; 2023-04-17 to current/open; source msha-controller-operator-history