# Relationship history for MSHA mine 3700186

Current hierarchy: **Monica  Donovan; Michael  O'Sullivan → Patriot Excavating Drilling & Blasting Inc → PATRIOT EXCAVATING DRILLING & BL**

- 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:** Patriot Excavating Drilling & Blasting Inc → PATRIOT EXCAVATING DRILLING & BL; 1997-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Monica  Donovan et al → PATRIOT EXCAVATING DRILLING & BL; 1997-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Monica  Donovan et al → Patriot Excavating Drilling & Blasting Inc; 1997-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael  O'Sullivan et al → Patriot Excavating Drilling & Blasting Inc; 1997-03-01 to current/open; source msha-controller-operator-history