# Relationship history for MSHA mine 3303804

Current hierarchy: **Mc Cort Michael B → Mack Energy Company → Vinton 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:** Mc Cort Michael B → Vinton Strip; 1973-12-06 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Mack Energy Company → Vinton Strip; 1980-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mc Cort Michael B → Mack Energy Company; 1980-02-01 to current/open; source msha-controller-operator-history