# Relationship history for MSHA mine 2800518

Current hierarchy: **Jason N  Cofrancesco → Grinnell Recycling Inc. → Grinnel Enterprises Inc Sand & Gravel**

- 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:** Grinnell Enterprises Inc → Grinnel Enterprises Inc Sand & Gravel; 1950-01-01 to 2005-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Jason N  Cofrancesco → Grinnel Enterprises Inc Sand & Gravel; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jason N  Cofrancesco → Grinnell Enterprises Inc; 1950-01-01 to 2005-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Grinnell Recycling Inc. → Grinnel Enterprises Inc Sand & Gravel; 2005-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Jason N  Cofrancesco → Grinnel Enterprises Inc Sand & Gravel; 2005-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jason N  Cofrancesco → Grinnell Recycling Inc.; 2005-06-01 to current/open; source msha-controller-operator-history