# Relationship history for MSHA mine 4607531

Current hierarchy: **Stephens J T → Black Hills Mining 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:** Stephens J T → No 1 Surface; 1983-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Cub Branch Development Company → No 1 Surface; 1988-06-01 to 1988-08-17; source msha-controller-operator-history
- **controller_controls_mine:** Smith Daniel F → No 1 Surface; 1988-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Smith Daniel F → Cub Branch Development Company; 1988-06-01 to 1988-08-17; source msha-controller-operator-history
- **operator_operates_mine:** Black Hills Mining Inc → No 1 Surface; 1988-08-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Stephens J T → Black Hills Mining Inc; 1988-08-18 to current/open; source msha-controller-operator-history