# Relationship history for MSHA mine 4503656

Current hierarchy: **Rusty  Gill → R.G. Crushing Inc. → Portable #1**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** R.G. Construction → Portable #1; 2009-02-18 to 2012-06-21; source msha-controller-operator-history
- **controller_controls_mine:** Rusty  Gill → Portable #1; 2009-02-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rusty  Gill → R.G. Construction; 2009-02-18 to 2012-06-21; source msha-controller-operator-history
- **operator_operates_mine:** R.G. Crushing Inc. → Portable #1; 2012-06-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Rusty  Gill → Portable #1; 2012-06-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rusty  Gill → R.G. Crushing Inc.; 2012-06-22 to current/open; source msha-controller-operator-history