# Relationship history for MSHA mine 3303917

Current hierarchy: **Ohio Coal & Construction Corp → Ohio Coal & Construction Corp → 39 Stoneplant**

- 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:** Ohio Coal & Construction Corp → 39 Stoneplant; 1982-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ohio Coal & Construction Corp → 39 Stoneplant; 1982-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ohio Coal & Construction Corp → Ohio Coal & Construction Corp; 1982-10-01 to current/open; source msha-controller-operator-history