# Relationship history for MSHA mine 3608212

Current hierarchy: **Wajoic Richard E → Serfco Inc → Whitney #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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Serfco Inc → Whitney #1; 1990-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Wajoic Richard E → Whitney #1; 1990-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wajoic Richard E → Serfco Inc; 1990-11-01 to current/open; source msha-controller-operator-history