# Relationship history for MSHA mine 3101273

Current hierarchy: **Overcash Ronald G → Overcash Gravel & Grading → Overcash 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:** Pless Brothers Grading → Overcash Pit; 1950-01-01 to 1982-11-22; source msha-controller-operator-history
- **controller_controls_mine:** Henry L  Pless et al → Overcash Pit; 1950-01-01 to 1982-11-22; source msha-controller-operator-history
- **controller_controls_operator:** Henry L  Pless et al → Pless Brothers Grading; 1950-01-01 to 1982-11-22; source msha-controller-operator-history
- **operator_operates_mine:** Overcash Gravel & Grading → Overcash Pit; 1982-11-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Overcash Ronald G → Overcash Pit; 1982-11-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Overcash Ronald G → Overcash Gravel & Grading; 1982-11-23 to current/open; source msha-controller-operator-history