# Relationship history for MSHA mine 3602651

Current hierarchy: **Vincent  Kassa → Silverbrook Anthracite Inc → No 18 Mine-Wanamie Colliery**

- 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

- **operator_operates_mine:** Blue Coal Corp → No 18 Mine-Wanamie Colliery; 1950-01-01 to 1973-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Gillen Thomas J → No 18 Mine-Wanamie Colliery; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gillen Thomas J → Blue Coal Corp; 1950-01-01 to 1973-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Vincent  Kassa → No 18 Mine-Wanamie Colliery; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Blue Coal Corp → No 18 Mine-Wanamie Colliery; 1974-01-01 to 1974-02-12; source msha-controller-operator-history
- **controller_controls_mine:** Great American Coal Company → No 18 Mine-Wanamie Colliery; 1974-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Great American Coal Company → Blue Coal Corp; 1974-01-01 to 1974-02-12; source msha-controller-operator-history
- **operator_operates_mine:** Silverbrook Anthracite Inc → No 18 Mine-Wanamie Colliery; 1974-02-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vincent  Kassa → Silverbrook Anthracite Inc; 1974-02-13 to current/open; source msha-controller-operator-history