# Relationship history for MSHA mine 0801353

Current hierarchy: **Dickerson Group Inc → Dickerson Aggregates Inc → 304th Street Quarry**

- 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:** Dickerson Group Inc → 304th Street Quarry; 1979-12-28 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Dickerson Aggregates Inc → 304th Street Quarry; 2006-11-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dickerson Group Inc → Dickerson Aggregates Inc; 2006-11-14 to current/open; source msha-controller-operator-history