# Relationship history for MSHA mine 4404060

Current hierarchy: **Stanley Kenneth D → Sandy Ridge Coal Corp → No 1 Strip 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:** Sandy Ridge Coal Corp → No 1 Strip Mine; 1975-04-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Stanley Kenneth D Et Al → No 1 Strip Mine; 1975-04-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Stanley Kenneth D Et Al → Sandy Ridge Coal Corp; 1975-04-22 to current/open; source msha-controller-operator-history