# Relationship history for MSHA mine 1517081

Current hierarchy: **John M  Potter; Thomas A  Potter → Sunny Ridge Mining Company Inc → No 9**

- 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

- **controller_controls_mine:** Thomas A  Potter et al → No 9; 1987-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sunny Ridge Mining Company Inc → No 9; 1991-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas A  Potter et al → Sunny Ridge Mining Company Inc; 1991-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John M  Potter et al → Sunny Ridge Mining Company Inc; 1991-06-01 to current/open; source msha-controller-operator-history