# Relationship history for MSHA mine 0102431

Current hierarchy: **Pendley Vernon → Naco Mining Company Inc → Natural Bridge #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

- **operator_operates_mine:** Naco Mining Company Inc → Natural Bridge #1; 1982-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Pendley Vernon → Natural Bridge #1; 1982-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pendley Vernon → Naco Mining Company Inc; 1982-01-01 to current/open; source msha-controller-operator-history