# Relationship history for MSHA mine 3601956

Current hierarchy: **Bush Ronald → Ronald Bush Coal Company → Skidmore Slope 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

- **operator_operates_mine:** Bush Coal Company → Skidmore Slope Mine; 1950-01-01 to 1979-10-21; source msha-controller-operator-history
- **controller_controls_mine:** Bush Earl → Skidmore Slope Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bush Earl → Bush Coal Company; 1950-01-01 to 1979-10-21; source msha-controller-operator-history
- **operator_operates_mine:** Ronald Bush Coal Company → Skidmore Slope Mine; 1979-10-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bush Ronald → Skidmore Slope Mine; 1979-10-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bush Ronald → Ronald Bush Coal Company; 1979-10-22 to current/open; source msha-controller-operator-history