# Relationship history for MSHA mine 3304473

Current hierarchy: **Carl  Baker Jr; David  Skinner → BELPRE SAND & GRAVEL CO. → BELPRE 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Belpre Sand & Gravel Co. → BELPRE SAND & GRAVEL; 2001-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Carl  Baker Jr et al → BELPRE SAND & GRAVEL; 2001-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Carl  Baker Jr et al → Belpre Sand & Gravel Co.; 2001-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David  Skinner  et al → Belpre Sand & Gravel Co.; 2001-01-01 to current/open; source msha-controller-operator-history