# Relationship history for MSHA mine 2002563

Current hierarchy: **Hocking Clarence → George Hocking Construction Company → Gogebic County Sand & Gravel**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Hocking Clarence → Gogebic County Sand & Gravel; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** George Hocking Construction Company → Gogebic County Sand & Gravel; 1980-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hocking Clarence → George Hocking Construction Company; 1980-06-01 to current/open; source msha-controller-operator-history