# Relationship history for MSHA mine 4402176

Current hierarchy: **Hylton Walter & Mary → Little B Coal Company → No 1 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:** Hylton & Collins Coal Company → No 1 Strip; 1950-01-01 to 1973-12-01; source msha-controller-operator-history
- **controller_controls_mine:** Hylton & Collins Coal Company → No 1 Strip; 1950-01-01 to 1973-12-01; source msha-controller-operator-history
- **controller_controls_operator:** Hylton & Collins Coal Company → Hylton & Collins Coal Company; 1950-01-01 to 1973-12-01; source msha-controller-operator-history
- **operator_operates_mine:** Little B Coal Company → No 1 Strip; 1973-12-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hylton Walter & Mary → No 1 Strip; 1973-12-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hylton Walter & Mary → Little B Coal Company; 1973-12-02 to current/open; source msha-controller-operator-history