# Relationship history for MSHA mine 1601351

Current hierarchy: **Ronnie  Schilling; Tanda  Schilling → Gravel Supplies Inc → PLANT 1**

- 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:** Gravel Supplies Inc → PLANT 1; 1999-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Tanda  Schilling  et al → PLANT 1; 1999-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tanda  Schilling  et al → Gravel Supplies Inc; 1999-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ronnie  Schilling  et al → Gravel Supplies Inc; 1999-05-01 to current/open; source msha-controller-operator-history