# Relationship history for MSHA mine 1516306

Current hierarchy: **Smith Tony → Smith & Mc Cowan Construction Inc → Strip**

- 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:** Smith & Mc Cowan Construction Inc → Strip; 1988-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Smith Tony Et Al → Strip; 1988-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Smith Tony Et Al → Smith & Mc Cowan Construction Inc; 1988-02-01 to current/open; source msha-controller-operator-history