# Relationship history for MSHA mine 0600221

Current hierarchy: **Benjamin W  Dunning → DUNNING INDUSTRIES INC → BRICKYARD PIT AND MILL**

- 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

- **operator_operates_mine:** Dunning Sand & Gravel Company Inc → BRICKYARD PIT AND MILL; 1950-01-01 to 2022-01-26; source msha-controller-operator-history
- **controller_controls_mine:** Benjamin W  Dunning → BRICKYARD PIT AND MILL; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Benjamin W  Dunning → Dunning Sand & Gravel Company Inc; 1950-01-01 to 2022-01-26; source msha-controller-operator-history
- **controller_controls_mine:** Benjamin W  Dunning → BRICKYARD PIT AND MILL; 2021-09-14 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Dunning Industries Inc → BRICKYARD PIT AND MILL; 2022-01-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Benjamin W  Dunning → Dunning Industries Inc; 2022-01-27 to current/open; source msha-controller-operator-history