# Relationship history for MSHA mine 3400898

Current hierarchy: **Watts Cleal → Hfco Inc → Tucker Mine**

- 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:** Hfco Inc → Tucker Mine; 1975-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Watts Cleal → Tucker Mine; 1975-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Watts Cleal → Hfco Inc; 1975-06-01 to current/open; source msha-controller-operator-history