# Relationship history for MSHA mine 1515251

Current hierarchy: **Saylor Delbert & Darlene Roberts → Dan Del Coals Inc → Wallins No 3**

- 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:** Saylor Delbert & Darlene Roberts → Wallins No 3; 1982-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Dan Del Coals Inc → Wallins No 3; 1985-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Saylor Delbert & Darlene Roberts → Dan Del Coals Inc; 1985-06-01 to current/open; source msha-controller-operator-history