# Relationship history for MSHA mine 4503514

Current hierarchy: **Mike  Carlson → Mike Carlson Enterprises 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Mike  Carlson → Portable #1; 1996-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Mike Carlson Enterprises Inc → Portable #1; 2002-08-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mike  Carlson → Mike Carlson Enterprises Inc; 2002-08-06 to current/open; source msha-controller-operator-history