# Relationship history for MSHA mine 4604374

Current hierarchy: **Staples T D → Sangamore Coal Company Inc → Surface Mine No 2**

- 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:** Staples T D → Surface Mine No 2; 1973-08-02 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sangamore Coal Company Inc → Surface Mine No 2; 1974-11-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Staples T D → Sangamore Coal Company Inc; 1974-11-18 to current/open; source msha-controller-operator-history