# Relationship history for MSHA mine 1302376

Current hierarchy: **Kent  Stuart; Bruce  Barnhart → Rock Hard Recycling Inc → Portable #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:** Rock Hard Concrete Recycling → Portable #1; 2008-09-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bruce  Barnhart et al → Portable #1; 2008-09-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bruce  Barnhart et al → Rock Hard Concrete Recycling; 2008-09-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kent  Stuart et al → Rock Hard Concrete Recycling; 2008-09-10 to current/open; source msha-controller-operator-history