# Relationship history for MSHA mine 3200741

Current hierarchy: **Wachter Gail → Gail Wachter Investments → Portable Wash Plant**

- 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:** Wachter Lance → Portable Wash Plant; 1986-05-08 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Dakota Sand & Gravel Company → Portable Wash Plant; 1994-06-01 to 1994-09-05; source msha-controller-operator-history
- **controller_controls_operator:** Wachter Lance → Dakota Sand & Gravel Company; 1994-06-01 to 1994-09-05; source msha-controller-operator-history
- **operator_operates_mine:** Gail Wachter Investments → Portable Wash Plant; 1994-09-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Wachter Gail → Portable Wash Plant; 1994-09-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wachter Gail → Gail Wachter Investments; 1994-09-06 to current/open; source msha-controller-operator-history