# Relationship history for MSHA mine 2103142

Current hierarchy: **Michael J  Ahlfs; Tom J  Ahlfs → Ottertail Aggregate Inc → Ottertail Aggregate #1**

- 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 → Ottertail Aggregate #1; 1995-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** James E Ahlfs Const → Ottertail Aggregate #1; 1997-06-01 to 2004-04-30; source msha-controller-operator-history
- **controller_controls_operator:** James E  Ahlfs → James E Ahlfs Const; 1997-06-01 to 2004-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Ottertail Aggregate Inc → Ottertail Aggregate #1; 2004-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** James E  Ahlfs → Ottertail Aggregate #1; 2004-05-01 to 2009-07-21; source msha-controller-operator-history
- **controller_controls_operator:** James E  Ahlfs → Ottertail Aggregate Inc; 2004-05-01 to 2009-07-21; source msha-controller-operator-history
- **controller_controls_mine:** Michael J  Ahlfs et al → Ottertail Aggregate #1; 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
- **controller_controls_operator:** Tom J  Ahlfs et al → Ottertail Aggregate Inc; 2009-07-22 to current/open; source msha-controller-operator-history