# Relationship history for MSHA mine 3102233

Current hierarchy: **Barnhill Contracting Company → Barnhill Contracting Company → Portable SC-7**

- 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:** Barnhill Contracting Company → Portable SC-7; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** William D  Mc Lean  et al → Portable SC-7; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Barnes Paving Company Inc → Portable SC-7; 2008-04-22 to 2012-02-01; source msha-controller-operator-history
- **controller_controls_operator:** William D  Mc Lean  et al → Barnes Paving Company Inc; 2008-04-22 to 2012-02-01; source msha-controller-operator-history
- **controller_controls_operator:** James D  Williamson  et al → Barnes Paving Company Inc; 2008-04-22 to 2012-02-01; source msha-controller-operator-history
- **operator_operates_mine:** Barnhill Contracting Company → Portable SC-7; 2012-02-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Barnhill Contracting Company → Barnhill Contracting Company; 2012-02-02 to current/open; source msha-controller-operator-history