# Relationship history for MSHA mine 1512619

Current hierarchy: **Newberry Ronald → Sandy Rock Coal Company Inc → No 1 Mine**

- 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:** Newberry Ronald Et Al → No 1 Mine; 1980-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sandy Rock Coal Company Inc → No 1 Mine; 1980-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Newberry Ronald Et Al → Sandy Rock Coal Company Inc; 1980-11-01 to current/open; source msha-controller-operator-history