# Relationship history for MSHA mine 3607449

Current hierarchy: **Vincent  Kassa → Silverbrook Anthracite, Inc. → Maltby Bank Operation  #2**

- 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:** Vincent  Kassa → Maltby Bank Operation  #2; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Kenzakoski Brothers → Maltby Bank Operation  #2; 1983-04-01 to 2009-03-01; source msha-controller-operator-history
- **controller_controls_mine:** Kenzakoski Joseph Et Al → Maltby Bank Operation  #2; 1983-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kenzakoski Joseph Et Al → Kenzakoski Brothers; 1983-04-01 to 2009-03-01; source msha-controller-operator-history
- **operator_operates_mine:** Silverbrook Anthracite, Inc. → Maltby Bank Operation  #2; 2009-03-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vincent  Kassa → Silverbrook Anthracite, Inc.; 2009-03-02 to current/open; source msha-controller-operator-history