# Relationship history for MSHA mine 2103148

Current hierarchy: **Mark  Amundson → Amundson Dig → Bloch Pit**

- 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:** Grunewald Gravel → Bloch Pit; 1997-07-01 to 2008-05-20; source msha-controller-operator-history
- **controller_controls_mine:** Ed  Grunewald → Bloch Pit; 1997-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ed  Grunewald → Grunewald Gravel; 1997-07-01 to 2008-05-20; source msha-controller-operator-history
- **operator_operates_mine:** Amundson Dig → Bloch Pit; 2008-05-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mark  Amundson → Bloch Pit; 2008-05-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mark  Amundson → Amundson Dig; 2008-05-21 to current/open; source msha-controller-operator-history