# Relationship history for MSHA mine 4000258

Current hierarchy: **Cox Franklin C → C L & C 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Wolf Ridge Coal Company → No 1 Strip; 1950-01-01 to 1974-03-18; source msha-controller-operator-history
- **controller_controls_mine:** Walls Reid → No 1 Strip; 1950-01-01 to 1974-03-18; source msha-controller-operator-history
- **controller_controls_operator:** Walls Reid → Wolf Ridge Coal Company; 1950-01-01 to 1974-03-18; source msha-controller-operator-history
- **operator_operates_mine:** C L & C Coal Company → No 1 Strip; 1974-03-19 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cox Franklin C → No 1 Strip; 1974-03-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cox Franklin C → C L & C Coal Company; 1974-03-19 to current/open; source msha-controller-operator-history