# Relationship history for MSHA mine 4502626

Current hierarchy: **Lassila Phil → Excel Construction & Equipment Inc → West Pit**

- 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:** Jim West Inc → West Pit; 1979-01-01 to 1987-01-01; source msha-controller-operator-history
- **controller_controls_mine:** West Jim Sr → West Pit; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** West Jim Sr → Jim West Inc; 1979-01-01 to 1987-01-01; source msha-controller-operator-history
- **operator_operates_mine:** Excel Construction & Equipment Inc → West Pit; 1987-01-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lassila Phil → West Pit; 1987-01-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lassila Phil → Excel Construction & Equipment Inc; 1987-01-02 to current/open; source msha-controller-operator-history