# Relationship history for MSHA mine 4201912

Current hierarchy: **Cason Todd  Stratton → Hurricane Ready Mix → Airport Pit**

- 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

- **operator_operates_mine:** Stratton & Son → Airport Pit; 1985-01-01 to 1989-02-15; source msha-controller-operator-history
- **controller_controls_mine:** Darwin M  Stratton → Airport Pit; 1985-01-01 to 1989-02-15; source msha-controller-operator-history
- **controller_controls_operator:** Darwin M  Stratton → Stratton & Son; 1985-01-01 to 1989-02-15; source msha-controller-operator-history
- **operator_operates_mine:** Darwin Stratton & Son Inc → Airport Pit; 1989-02-16 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_mine:** Clayton Darwin  Stratton → Airport Pit; 1989-02-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Clayton Darwin  Stratton → Darwin Stratton & Son Inc; 1989-02-16 to 2007-11-15; source msha-controller-operator-history
- **operator_operates_mine:** Hurricane Ready Mix → Airport Pit; 2007-11-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Todd C  Stratton → Airport Pit; 2007-11-16 to 2019-10-08; source msha-controller-operator-history
- **controller_controls_operator:** Todd C  Stratton → Hurricane Ready Mix; 2007-11-16 to 2019-10-08; source msha-controller-operator-history
- **controller_controls_mine:** Cason Todd  Stratton → Airport Pit; 2019-10-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cason Todd  Stratton → Hurricane Ready Mix; 2019-10-09 to current/open; source msha-controller-operator-history