# Relationship history for MSHA mine 1102577

Current hierarchy: **Henderson Archie Bob → Southern Illinois Mining Company → Simco Mine No 1**

- 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:** Southern Illinois Management → Simco Mine No 1; 1976-11-01 to 1977-07-10; source msha-controller-operator-history
- **controller_controls_mine:** Spiller Gary → Simco Mine No 1; 1976-11-01 to 1977-07-10; source msha-controller-operator-history
- **controller_controls_operator:** Spiller Gary → Southern Illinois Management; 1976-11-01 to 1977-07-10; source msha-controller-operator-history
- **operator_operates_mine:** Southern Illinois Mining Company → Simco Mine No 1; 1977-07-11 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Henderson Archie Bob → Simco Mine No 1; 1977-07-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Henderson Archie Bob → Southern Illinois Mining Company; 1977-07-11 to current/open; source msha-controller-operator-history