# Relationship history for MSHA mine 3000956

Current hierarchy: **James  Barker → Roanoke Sand & Gravel  Corporation → Roanoke Sand & Gravel Corporation**

- 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:** Roanoke Marbro Sand & Gravel Corp → Roanoke Sand & Gravel Corporation; 1950-01-01 to 1984-12-11; source msha-controller-operator-history
- **controller_controls_mine:** Anna  Marino → Roanoke Sand & Gravel Corporation; 1950-01-01 to 1984-12-11; source msha-controller-operator-history
- **controller_controls_operator:** Anna  Marino → Roanoke Marbro Sand & Gravel Corp; 1950-01-01 to 1984-12-11; source msha-controller-operator-history
- **operator_operates_mine:** Roanoke Sand & Gravel  Corporation → Roanoke Sand & Gravel Corporation; 1984-12-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** James  Barker → Roanoke Sand & Gravel Corporation; 1984-12-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James  Barker → Roanoke Sand & Gravel  Corporation; 1984-12-12 to current/open; source msha-controller-operator-history