# Relationship history for MSHA mine 1513546

Current hierarchy: **Igel George J → Spencer Fork Mining → No 1 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Spencer Fork Mining → No 1 Strip; 1982-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Igel George J → No 1 Strip; 1982-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Igel George J → Spencer Fork Mining; 1982-06-01 to current/open; source msha-controller-operator-history