# Relationship history for MSHA mine 2003121

Current hierarchy: **Jeffrey M  Rydahl → Rydahl Industries → M57 PIT**

- 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:** Rydahl Industries → M57 PIT; 1999-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Jeffrey M  Rydahl → M57 PIT; 1999-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jeffrey M  Rydahl → Rydahl Industries; 1999-06-01 to current/open; source msha-controller-operator-history