# Relationship history for MSHA mine 3200879

Current hierarchy: **John Steven  Kulstad → John's  Sand & Gravel → Crusher # 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** John's  Sand & Gravel → Crusher # 1; 2011-03-25 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John Steven  Kulstad et al → Crusher # 1; 2011-03-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John Steven  Kulstad et al → John's  Sand & Gravel; 2011-03-25 to current/open; source msha-controller-operator-history