# Relationship history for MSHA mine 2001254

Current hierarchy: **Edward C  Levy Jr → American Aggregates of Michigan Inc → A A Grange Hall Rd Plant**

- 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:** Kurtz Gravel Company → A A Grange Hall Rd Plant; 1950-01-01 to 2007-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Robert D  Kurtz et al → A A Grange Hall Rd Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert D  Kurtz et al → Kurtz Gravel Company; 1950-01-01 to 2007-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Kevin B  Kurtz et al → Kurtz Gravel Company; 1950-01-01 to 2007-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Edward C  Levy Jr et al → A A Grange Hall Rd Plant; 1997-05-31 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** American Aggregates of Michigan Inc → A A Grange Hall Rd Plant; 2007-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edward C  Levy Jr et al → American Aggregates of Michigan Inc; 2007-04-01 to current/open; source msha-controller-operator-history