# Relationship history for MSHA mine 2103109

Current hierarchy: **Aggregate Industries PLC → Camas Minndak Inc → OTTERTAIL 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

- **operator_operates_mine:** Ahlfs Construction → OTTERTAIL PORTABLE CRUSHER; 1995-08-01 to 1998-08-17; source msha-controller-operator-history
- **controller_controls_mine:** James E  Ahlfs → OTTERTAIL PORTABLE CRUSHER; 1995-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James E  Ahlfs → Ahlfs Construction; 1995-08-01 to 1998-08-17; source msha-controller-operator-history
- **controller_controls_mine:** Aggregate Industries PLC → OTTERTAIL PORTABLE CRUSHER; 1997-05-14 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Camas Minndak Inc → OTTERTAIL PORTABLE CRUSHER; 1998-08-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Aggregate Industries PLC → Camas Minndak Inc; 1998-08-18 to current/open; source msha-controller-operator-history