# Relationship history for MSHA mine 2402372

Current hierarchy: **Norman K Hanson → Sickler Shale & Gravel, Inc. → Sickler  Shale & Gravel Portable Crusher**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Sickler Shale & Gravel, Inc. → Sickler  Shale & Gravel Portable Crusher; 2005-06-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Norman K Hanson → Sickler  Shale & Gravel Portable Crusher; 2005-06-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Norman K Hanson → Sickler Shale & Gravel, Inc.; 2005-06-08 to current/open; source msha-controller-operator-history