# Relationship history for MSHA mine 3503606

Current hierarchy: **David G  Gould; Donna L  Gould → Coos Bay Timber Operators, Inc. → Portable Symons Cone**

- 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:** David G  Gould et al → Portable Symons Cone; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Coos Bay Timber Operators, Inc. → Portable Symons Cone; 2004-10-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David G  Gould et al → Coos Bay Timber Operators, Inc.; 2004-10-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Donna L  Gould et al → Coos Bay Timber Operators, Inc.; 2004-10-18 to current/open; source msha-controller-operator-history