# Relationship history for MSHA mine 1515963

Current hierarchy: **Bowling Jerry W → Unicorn Mining → Unicorn #2**

- 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:** Unicorn Mining → Unicorn #2; 1987-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bowling Jerry W → Unicorn #2; 1987-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bowling Jerry W → Unicorn Mining; 1987-03-01 to current/open; source msha-controller-operator-history