# Relationship history for MSHA mine 4401435

Current hierarchy: **Hollow Katie Coal Company → Katie Hollow Coal Co → No 2 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:** S & S Coal Co Inc → No 2 Strip; 1950-01-01 to 1975-09-01; source msha-controller-operator-history
- **controller_controls_mine:** Strouth Kyle → No 2 Strip; 1950-01-01 to 1975-09-01; source msha-controller-operator-history
- **controller_controls_operator:** Strouth Kyle → S & S Coal Co Inc; 1950-01-01 to 1975-09-01; source msha-controller-operator-history
- **operator_operates_mine:** Katie Hollow Coal Co → No 2 Strip; 1975-09-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hollow Katie Coal Company → No 2 Strip; 1975-09-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hollow Katie Coal Company → Katie Hollow Coal Co; 1975-09-02 to current/open; source msha-controller-operator-history