# Relationship history for MSHA mine 3503579

Current hierarchy: **Steve  Ausland; Robert S  Copeland → Copeland Sand & Gravel Inc → Copeland Portable Crusher**

- 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:** Robert S  Copeland  et al → Copeland Portable Crusher; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Copeland Sand & Gravel Inc → Copeland Portable Crusher; 2003-05-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert S  Copeland  et al → Copeland Sand & Gravel Inc; 2003-05-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Steve  Ausland  et al → Copeland Sand & Gravel Inc; 2003-05-07 to current/open; source msha-controller-operator-history