# Relationship history for MSHA mine 3608069

Current hierarchy: **Soster Roy → Soster Quarry → Roy Soster**

- 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:** Lobb Mining → Roy Soster; 1989-02-01 to 1990-09-18; source msha-controller-operator-history
- **controller_controls_mine:** Lobb William T Jr → Roy Soster; 1989-02-01 to 1990-09-18; source msha-controller-operator-history
- **controller_controls_operator:** Lobb William T Jr → Lobb Mining; 1989-02-01 to 1990-09-18; source msha-controller-operator-history
- **operator_operates_mine:** Soster Quarry → Roy Soster; 1990-09-19 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Soster Roy → Roy Soster; 1990-09-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Soster Roy → Soster Quarry; 1990-09-19 to current/open; source msha-controller-operator-history