# Relationship history for MSHA mine 3303827

Current hierarchy: **Arnold  Rosebrock → Ward Materials Inc → Ward Material'S Incorporated**

- 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

- **controller_controls_mine:** Reese Robert R → Ward Material'S Incorporated; 1980-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Rockport Sand & Gravel Company Inc → Ward Material'S Incorporated; 1980-05-01 to 1988-05-15; source msha-controller-operator-history
- **controller_controls_operator:** Reese Robert R → Rockport Sand & Gravel Company Inc; 1980-05-01 to 1988-05-15; source msha-controller-operator-history
- **operator_operates_mine:** Ward Materials Inc → Ward Material'S Incorporated; 1988-05-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Arnold  Rosebrock → Ward Material'S Incorporated; 1988-05-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Arnold  Rosebrock → Ward Materials Inc; 1988-05-16 to current/open; source msha-controller-operator-history