# Relationship history for MSHA mine 4606778

Current hierarchy: **Delta Industries Inc - Md → Delta Mining Inc → Mine 33**

- 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:** R & R Coal Contracting Inc → Mine 33; 1984-05-01 to 1988-10-19; source msha-controller-operator-history
- **controller_controls_mine:** Ryder Willie A → Mine 33; 1984-05-01 to 1989-07-20; source msha-controller-operator-history
- **controller_controls_operator:** Ryder Willie A → R & R Coal Contracting Inc; 1984-05-01 to 1988-10-19; source msha-controller-operator-history
- **operator_operates_mine:** Delta Mining Inc → Mine 33; 1988-10-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Delta Industries Inc - Md → Mine 33; 1988-10-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Delta Industries Inc - Md → Delta Mining Inc; 1988-10-20 to current/open; source msha-controller-operator-history