# Relationship history for MSHA mine 3302926

Current hierarchy: **Bates Gene D → Upland Contracting Company Inc → Polivka 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

- **operator_operates_mine:** Upland Contracting Company Inc → Polivka Strip; 1973-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bates Gene D → Polivka Strip; 1973-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bates Gene D → Upland Contracting Company Inc; 1973-01-01 to current/open; source msha-controller-operator-history