# Relationship history for MSHA mine 0203195

Current hierarchy: **Tom  Drysdale → DBA Construction → Vulcan 24th Street Pit**

- 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:** DBA Construction → Vulcan 24th Street Pit; 2007-10-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Tom  Drysdale → Vulcan 24th Street Pit; 2007-10-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tom  Drysdale → DBA Construction; 2007-10-02 to current/open; source msha-controller-operator-history