# Relationship history for MSHA mine 4607118

Current hierarchy: **Swartzenberg Brian → Northeastern Mining Of West Virginia Inc → Crellin**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Techwell Mining Inc → Crellin; 1986-05-01 to 1987-06-07; source msha-controller-operator-history
- **controller_controls_mine:** Techwell Mining Inc & Ronald Bolyard → Crellin; 1986-05-01 to 1987-06-07; source msha-controller-operator-history
- **controller_controls_operator:** Techwell Mining Inc & Ronald Bolyard → Techwell Mining Inc; 1986-05-01 to 1987-06-07; source msha-controller-operator-history
- **operator_operates_mine:** Northeastern Mining Of West Virginia Inc → Crellin; 1987-06-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Swartzenberg Brian → Crellin; 1987-06-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Swartzenberg Brian → Northeastern Mining Of West Virginia Inc; 1987-06-08 to current/open; source msha-controller-operator-history