# Relationship history for MSHA mine 3606690

Current hierarchy: **Tonozzi Arthur-G Wolkos & J Tani → Canon Ltd → Laurel Strip**

- 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:** Laurel Land Development Limited → Laurel Strip; 1978-06-01 to 1979-08-07; source msha-controller-operator-history
- **controller_controls_mine:** Piatti Victor C & Joseph Trusio → Laurel Strip; 1978-06-01 to 1979-08-07; source msha-controller-operator-history
- **controller_controls_operator:** Piatti Victor C & Joseph Trusio → Laurel Land Development Limited; 1978-06-01 to 1979-08-07; source msha-controller-operator-history
- **operator_operates_mine:** Canon Ltd → Laurel Strip; 1979-08-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Tonozzi Arthur-G Wolkos & J Tani → Laurel Strip; 1979-08-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tonozzi Arthur-G Wolkos & J Tani → Canon Ltd; 1979-08-08 to current/open; source msha-controller-operator-history