# Relationship history for MSHA mine 3602720

Current hierarchy: **Bav Liquidating Corp → Avery Coal Company Inc → Christopher No 3 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:** W G Hartman Contracting Inc → Christopher No 3 Strip; 1950-01-01 to 1976-02-29; source msha-controller-operator-history
- **controller_controls_mine:** Hartman W G Contracting Inc → Christopher No 3 Strip; 1950-01-01 to 1976-02-29; source msha-controller-operator-history
- **controller_controls_operator:** Hartman W G Contracting Inc → W G Hartman Contracting Inc; 1950-01-01 to 1976-02-29; source msha-controller-operator-history
- **operator_operates_mine:** Avery Coal Company Inc → Christopher No 3 Strip; 1976-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bav Liquidating Corp → Christopher No 3 Strip; 1976-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bav Liquidating Corp → Avery Coal Company Inc; 1976-03-01 to current/open; source msha-controller-operator-history