# Relationship history for MSHA mine 4606224

Current hierarchy: **Mc Nicol Jack B → Riverside Industries Inc → Stephenson Mine**

- 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:** Mc Nicol Jack B → Stephenson Mine; 1980-07-12 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Riverside Industries Inc → Stephenson Mine; 1980-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mc Nicol Jack B → Riverside Industries Inc; 1980-09-01 to current/open; source msha-controller-operator-history