# Relationship history for MSHA mine 1700639

Current hierarchy: **Ralph E  Howard → Quick Stream Gravel → QUICK STREAM 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:** Quick Stream Gravel → QUICK STREAM GRAVEL; 1998-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ralph E  Howard → QUICK STREAM GRAVEL; 1998-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ralph E  Howard → Quick Stream Gravel; 1998-08-01 to current/open; source msha-controller-operator-history