# Relationship history for MSHA mine 3606164

Current hierarchy: **Erdley Martin L → M L Erdley Company → Erdley Bros 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:** M L Erdley Company → Erdley Bros Strip; 1976-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Erdley Martin L → Erdley Bros Strip; 1976-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Erdley Martin L → M L Erdley Company; 1976-07-01 to current/open; source msha-controller-operator-history