# Relationship history for MSHA mine 3607513

Current hierarchy: **Chiccini Michael A → Greenfield Contracting Company → Buck Run Strip**

- 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:** Avalanche Coal Company → Buck Run Strip; 1983-11-01 to 1984-11-22; source msha-controller-operator-history
- **controller_controls_mine:** Hutsko John M → Buck Run Strip; 1983-11-01 to 1984-11-22; source msha-controller-operator-history
- **controller_controls_operator:** Hutsko John M → Avalanche Coal Company; 1983-11-01 to 1984-11-22; source msha-controller-operator-history
- **operator_operates_mine:** Greenfield Contracting Company → Buck Run Strip; 1984-11-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Chiccini Michael A → Buck Run Strip; 1984-11-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chiccini Michael A → Greenfield Contracting Company; 1984-11-23 to current/open; source msha-controller-operator-history