# Relationship history for MSHA mine 2600211

Current hierarchy: **Gulf USA Corp → Bunker Hill Company → Caselton Mill**

- 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:** Bunker Hill Company → Caselton Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gulf USA Corp → Caselton Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gulf USA Corp → Bunker Hill Company; 1950-01-01 to current/open; source msha-controller-operator-history