# Relationship history for MSHA mine 4403525

Current hierarchy: **Elkins William T → Big Ten 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Elkins William T → No 2 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Mary Ruth Coal Corp → No 2 Mine; 1973-01-01 to 1974-10-16; source msha-controller-operator-history
- **controller_controls_mine:** Mary Ruth Coal Corp → No 2 Mine; 1973-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mary Ruth Coal Corp → Mary Ruth Coal Corp; 1973-01-01 to 1974-10-16; source msha-controller-operator-history
- **operator_operates_mine:** Big Ten Coal Corp → No 2 Mine; 1974-10-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Elkins William T → Big Ten Coal Corp; 1974-10-17 to current/open; source msha-controller-operator-history