# Relationship history for MSHA mine 2100497

Current hierarchy: **Central Allied Enterprises Inc → Central Allied Enterprises Inc → DANUBE WASHED SAND AND GRAVEL**

- 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

- **controller_controls_mine:** Central Allied Enterprises Inc → DANUBE WASHED SAND AND GRAVEL; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Danube Washed Sand & Gravel → DANUBE WASHED SAND AND GRAVEL; 1950-01-01 to 1986-07-30; source msha-controller-operator-history
- **controller_controls_mine:** Ellsworth A  Kaiser  et al → DANUBE WASHED SAND AND GRAVEL; 1950-01-01 to 1986-07-30; source msha-controller-operator-history
- **controller_controls_operator:** Ellsworth A  Kaiser  et al → Danube Washed Sand & Gravel; 1950-01-01 to 1986-07-30; source msha-controller-operator-history
- **operator_operates_mine:** Danube Washed Sand & Gravel Company → DANUBE WASHED SAND AND GRAVEL; 1986-07-31 to 1995-04-02; source msha-controller-operator-history
- **controller_controls_mine:** Richard  Schroeder  et al → DANUBE WASHED SAND AND GRAVEL; 1986-07-31 to 1995-04-02; source msha-controller-operator-history
- **controller_controls_operator:** Richard  Schroeder  et al → Danube Washed Sand & Gravel Company; 1986-07-31 to 1995-04-02; source msha-controller-operator-history
- **operator_operates_mine:** Central Allied Enterprises Inc → DANUBE WASHED SAND AND GRAVEL; 1995-04-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Central Allied Enterprises Inc → Central Allied Enterprises Inc; 1995-04-03 to current/open; source msha-controller-operator-history