# Relationship history for MSHA mine 3301909

Current hierarchy: **Vujnovic John → Krulock Inc → Jeffrey Grove**

- 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:** Krulock Inc → Jeffrey Grove; 1950-01-01 to 1978-03-13; source msha-controller-operator-history
- **controller_controls_mine:** George  Krulock → Jeffrey Grove; 1950-01-01 to 1978-03-13; source msha-controller-operator-history
- **controller_controls_operator:** George  Krulock → Krulock Inc; 1950-01-01 to 1978-03-13; source msha-controller-operator-history
- **controller_controls_mine:** Vujnovic John → Jeffrey Grove; 1978-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Krulock Inc → Jeffrey Grove; 1978-03-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vujnovic John → Krulock Inc; 1978-03-14 to current/open; source msha-controller-operator-history