# Relationship history for MSHA mine 3606329

Current hierarchy: **Berwind Corporation → Doe Valley Coal Company → Doe Valley Tipple**

- 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:** Doe Valley Coal Company → Doe Valley Tipple; 1977-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Berwind Corporation → Doe Valley Tipple; 1977-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Berwind Corporation → Doe Valley Coal Company; 1977-02-01 to current/open; source msha-controller-operator-history