# Relationship history for MSHA mine 1202198

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Aggregates → Portable Plant #1-801**

- 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 → Portable Plant #1-801; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** CSR Ltd → Portable Plant #1-801; 1990-02-02 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** American Aggregates Corp → Portable Plant #1-801; 1996-08-01 to 1997-05-27; source msha-controller-operator-history
- **controller_controls_operator:** CSR Ltd → American Aggregates Corp; 1996-08-01 to 1997-05-27; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Aggregates → Portable Plant #1-801; 1997-05-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Aggregates; 1997-05-28 to current/open; source msha-controller-operator-history