# Relationship history for MSHA mine 4103499

Current hierarchy: **Kunkel Ronald & George Wood → Bridge Valley Gravel → Plant #1**

- 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:** Bridge Valley Gravel → Plant #1; 1987-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Kunkel Ronald & George Wood Et Al → Plant #1; 1987-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kunkel Ronald & George Wood Et Al → Bridge Valley Gravel; 1987-11-01 to current/open; source msha-controller-operator-history