# Relationship history for MSHA mine 0404893

Current hierarchy: **Asea Brown Boveri Ltd (ABB) → Ione Energy Inc → Jackson Valley Open Pit Lignite Mining**

- 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:** Ione Energy Inc → Jackson Valley Open Pit Lignite Mining; 1987-08-01 to 1990-08-15; source msha-controller-operator-history
- **controller_controls_mine:** Cassel Thomas A V → Jackson Valley Open Pit Lignite Mining; 1987-08-01 to 1990-08-15; source msha-controller-operator-history
- **controller_controls_operator:** Cassel Thomas A V → Ione Energy Inc; 1987-08-01 to 1990-08-15; source msha-controller-operator-history
- **operator_operates_mine:** Ione Energy Inc → Jackson Valley Open Pit Lignite Mining; 1990-08-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Asea Brown Boveri Ltd (ABB) → Jackson Valley Open Pit Lignite Mining; 1990-08-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Asea Brown Boveri Ltd (ABB) → Ione Energy Inc; 1990-08-16 to current/open; source msha-controller-operator-history