# Relationship history for MSHA mine 1101915

Current hierarchy: **Zeigler Coal Holding Company → Old Ben Coal Company → Central Shop**

- 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:** Zeigler Coal Company → Central Shop; 1950-01-01 to 1985-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Houston Natural Gas Corp → Central Shop; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Houston Natural Gas Corp → Zeigler Coal Company; 1950-01-01 to 1985-01-31; source msha-controller-operator-history
- **operator_operates_mine:** Old Ben Coal Company → Central Shop; 1985-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Zeigler Coal Holding Company → Central Shop; 1985-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Zeigler Coal Holding Company → Old Ben Coal Company; 1985-02-01 to current/open; source msha-controller-operator-history