# Relationship history for MSHA mine 4607175

Current hierarchy: **Crites Rodger L → National Construction Company Inc → Barbour Co #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:** Crites Rodger L → Barbour Co #1; 1978-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** National Construction Company Inc → Barbour Co #1; 1986-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Crites Rodger L → National Construction Company Inc; 1986-08-01 to current/open; source msha-controller-operator-history