# Relationship history for MSHA mine 1512559

Current hierarchy: **Smith Tony → Maybe Coal Company → No 1 Surface**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Maybe Coal Company → No 1 Surface; 1980-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Smith Tony Et Al → No 1 Surface; 1980-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Smith Tony Et Al → Maybe Coal Company; 1980-10-01 to current/open; source msha-controller-operator-history