# Relationship history for MSHA mine 3304460

Current hierarchy: **Heidelberg Materials AG → Heidelberg Materials Midwest Agg, Inc. → Dry Fork Sand & 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Bunnell James → Dry Fork Sand & Gravel; 1950-01-01 to 2003-01-15; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Dry Fork Sand & Gravel; 1988-11-14 to 2007-08-22; source msha-controller-operator-history
- **operator_operates_mine:** James Bunnell Inc → Dry Fork Sand & Gravel; 2000-05-01 to 2008-08-14; source msha-controller-operator-history
- **controller_controls_operator:** Bunnell James → James Bunnell Inc; 2000-05-01 to 2003-01-15; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Dry Fork Sand & Gravel; 2003-01-16 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → James Bunnell Inc; 2003-01-16 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Dry Fork Sand & Gravel; 2007-08-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → James Bunnell Inc; 2007-08-23 to 2008-08-14; source msha-controller-operator-history
- **operator_operates_mine:** Heidelberg Materials Midwest Agg, Inc. → Dry Fork Sand & Gravel; 2008-08-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Heidelberg Materials Midwest Agg, Inc.; 2008-08-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Heidelberg Materials Midwest Agg, Inc.; 2008-08-15 to 2007-08-22; source msha-controller-operator-history