# Relationship history for MSHA mine 0101819

Current hierarchy: **Mc Donald John F → Serec Inc → Secondary Recovery System**

- 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:** Serec Inc → Secondary Recovery System; 1977-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mc Donald John F → Secondary Recovery System; 1977-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mc Donald John F → Serec Inc; 1977-11-01 to current/open; source msha-controller-operator-history