# Relationship history for MSHA mine 1515356

Current hierarchy: **Simmons Harold → D & S Contractors Inc → No 3 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Simmons Harold → No 3 Surface; 1984-08-04 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** D & S Contractors Inc → No 3 Surface; 1985-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Simmons Harold → D & S Contractors Inc; 1985-09-01 to current/open; source msha-controller-operator-history