# Relationship history for MSHA mine 1516521

Current hierarchy: **Great Western Resources Inc → Great Western Coal Inc → Smith #10**

- 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:** Great Western Resources Inc → Smith #10; 1987-02-04 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Great Western Coal Inc → Smith #10; 1988-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Great Western Resources Inc → Great Western Coal Inc; 1988-11-01 to current/open; source msha-controller-operator-history