# Relationship history for MSHA mine 0405147

Current hierarchy: **Skanska AB → Skanska → PORTABLE**

- 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:** Yeager Jacques S (Jack) → PORTABLE; 1979-01-01 to 2003-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Skanska → PORTABLE; 1991-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Yeager Jacques S (Jack) → Skanska; 1991-05-01 to 2003-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Skanska AB → PORTABLE; 2002-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Skanska AB → Skanska; 2002-09-01 to current/open; source msha-controller-operator-history