# Relationship history for MSHA mine 3607787

Current hierarchy: **Drebitko Andrew → Ad Coal Company → Bunns Diamond Strip**

- 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:** Drebitko Andrew → Bunns Diamond Strip; 1984-06-29 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ad Coal Company → Bunns Diamond Strip; 1986-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Drebitko Andrew → Ad Coal Company; 1986-03-01 to current/open; source msha-controller-operator-history