# Relationship history for MSHA mine 1515136

Current hierarchy: **Stephens J T → Black Hills Mining Inc → Vinson Branch**

- 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 → Vinson Branch; 1983-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Black Hills Mining Inc → Vinson Branch; 1985-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Stephens J T → Black Hills Mining Inc; 1985-03-01 to current/open; source msha-controller-operator-history