# Relationship history for MSHA mine 3607642

Current hierarchy: **Chiccini Michael A → Greenfield Contracting Company → Bottom Rock Strip Mine**

- 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

- **controller_controls_mine:** Chiccini Michael A → Bottom Rock Strip Mine; 1984-11-23 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Greenfield Contracting Company → Bottom Rock Strip Mine; 1984-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chiccini Michael A → Greenfield Contracting Company; 1984-12-01 to current/open; source msha-controller-operator-history