# Relationship history for MSHA mine 3901425

Current hierarchy: **Mike  Ford → J & M Gravel & Construction Inc → SCREENING PLANT**

- 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

- **operator_operates_mine:** J & M Gravel & Construction Inc → SCREENING PLANT; 1998-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mike  Ford → SCREENING PLANT; 1998-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mike  Ford → J & M Gravel & Construction Inc; 1998-06-01 to current/open; source msha-controller-operator-history