# Relationship history for MSHA mine 0102871

Current hierarchy: **Martin Marietta Materials Inc → Hoover Inc → Decatur 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:** Thomas S  Hoover → Decatur Quarry; 1950-01-01 to 2018-02-08; source msha-controller-operator-history
- **operator_operates_mine:** Hoover Inc → Decatur Quarry; 1990-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas S  Hoover → Hoover Inc; 1990-08-01 to 2018-02-08; source msha-controller-operator-history
- **controller_controls_mine:** Blue Water Industries Holdings LLC → Decatur Quarry; 2018-02-09 to 2024-04-04; source msha-controller-operator-history
- **controller_controls_operator:** Blue Water Industries Holdings LLC → Hoover Inc; 2018-02-09 to 2024-04-04; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → Decatur Quarry; 2024-04-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Hoover Inc; 2024-04-05 to current/open; source msha-controller-operator-history