# Relationship history for MSHA mine 4003355

Current hierarchy: **Vernon W  Houston → Wayne Houston Stone → Lick Creek 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Vernon W  Houston → Lick Creek Quarry; 2005-02-09 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Wayne Houston Stone → Lick Creek Quarry; 2009-06-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vernon W  Houston → Wayne Houston Stone; 2009-06-18 to current/open; source msha-controller-operator-history