# Relationship history for MSHA mine 2103592

Current hierarchy: **Michael J  Ahlfs; Tom J  Ahlfs → Ottertail Aggregate Inc → Screener**

- 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:** James E  Ahlfs → Screener; 2004-05-01 to 2009-07-21; source msha-controller-operator-history
- **operator_operates_mine:** Ottertail Aggregate Inc → Screener; 2007-06-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James E  Ahlfs → Ottertail Aggregate Inc; 2007-06-12 to 2009-07-21; source msha-controller-operator-history
- **controller_controls_mine:** Tom J  Ahlfs et al → Screener; 2009-07-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tom J  Ahlfs et al → Ottertail Aggregate Inc; 2009-07-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael J  Ahlfs et al → Ottertail Aggregate Inc; 2009-07-22 to current/open; source msha-controller-operator-history