# Relationship history for MSHA mine 2602309

Current hierarchy: **Don  Andress → Hollywood Gravel Company LP → Extec Turbo 735**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Don  Andress et al → Extec Turbo 735; 1988-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hollywood Gravel Company LP → Extec Turbo 735; 1997-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Don  Andress et al → Hollywood Gravel Company LP; 1997-01-01 to current/open; source msha-controller-operator-history