# Relationship history for MSHA mine 0405350

Current hierarchy: **Dennis  Troesh → Robertsons Ltd → CORONA**

- 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:** Michael  Tonkinson → CORONA; 1998-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Tonkco Corp → CORONA; 1998-08-01 to 2000-09-04; source msha-controller-operator-history
- **controller_controls_operator:** Michael  Tonkinson → Tonkco Corp; 1998-08-01 to 2000-09-04; source msha-controller-operator-history
- **operator_operates_mine:** Robertsons Ltd → CORONA; 2000-09-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dennis  Troesh → CORONA; 2000-09-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dennis  Troesh → Robertsons Ltd; 2000-09-05 to current/open; source msha-controller-operator-history