# Relationship history for MSHA mine 2003067

Current hierarchy: **Adams Frank → Adams Trucking & Excavating Inc → PORTABLE CEDAR RAPIDS**

- 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:** Adams Trucking & Excavating Inc → PORTABLE CEDAR RAPIDS; 1998-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Adams Frank → PORTABLE CEDAR RAPIDS; 1998-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Adams Frank → Adams Trucking & Excavating Inc; 1998-06-01 to current/open; source msha-controller-operator-history