# Relationship history for MSHA mine 3503616

Current hierarchy: **Steve  Ausland; Robert S  Copeland → Barlow Sand and Gravel LLC → Barlow Sand & Gravel LLC**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Barlow Sand and Gravel LLC → Barlow Sand & Gravel LLC; 2005-04-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Kelly C  Agnew → Barlow Sand & Gravel LLC; 2005-04-28 to 2006-03-15; source msha-controller-operator-history
- **controller_controls_operator:** Kelly C  Agnew → Barlow Sand and Gravel LLC; 2005-04-28 to 2006-03-15; source msha-controller-operator-history
- **controller_controls_mine:** Steve  Ausland  et al → Barlow Sand & Gravel LLC; 2006-03-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Steve  Ausland  et al → Barlow Sand and Gravel LLC; 2006-03-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert S  Copeland  et al → Barlow Sand and Gravel LLC; 2006-03-16 to current/open; source msha-controller-operator-history