# Relationship history for MSHA mine 4001830

Current hierarchy: **Hicks Dewey → D & H Coal Company Inc → No 1 Surface**

- 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

- **controller_controls_mine:** Hicks Dewey → No 1 Surface; 1974-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Vines Ridge Coal Company → No 1 Surface; 1975-05-26 to 1976-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Austin John & Ray → No 1 Surface; 1975-05-26 to 1976-01-31; source msha-controller-operator-history
- **controller_controls_operator:** Austin John & Ray → Vines Ridge Coal Company; 1975-05-26 to 1976-01-31; source msha-controller-operator-history
- **operator_operates_mine:** D & H Coal Company Inc → No 1 Surface; 1976-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hicks Dewey → D & H Coal Company Inc; 1976-02-01 to current/open; source msha-controller-operator-history