# Relationship history for MSHA mine 4403439

Current hierarchy: **Rose Avery → Elro Coal Corp → No 2 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:** Rose Avery → No 2 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Big Ten Coal Corp → No 2 Mine; 1950-01-01 to 1976-04-21; source msha-controller-operator-history
- **controller_controls_mine:** Elkins William T → No 2 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Elkins William T → Big Ten Coal Corp; 1950-01-01 to 1976-04-21; source msha-controller-operator-history
- **operator_operates_mine:** Elro Coal Corp → No 2 Mine; 1976-04-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rose Avery → Elro Coal Corp; 1976-04-22 to current/open; source msha-controller-operator-history