# Relationship history for MSHA mine 1516190

Current hierarchy: **Ball Ralph → Sterling Energy Inc → No 7**

- 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:** Ball Ralph → No 7; 1981-06-24 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sterling Energy Inc → No 7; 1987-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ball Ralph → Sterling Energy Inc; 1987-09-01 to current/open; source msha-controller-operator-history