# Relationship history for MSHA mine 4200648

Current hierarchy: **Lammert Tom → Lammert Mining → Vanadium Queen**

- 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:** Ray Small Mining Company → Vanadium Queen; 1950-01-01 to 1988-11-27; source msha-controller-operator-history
- **controller_controls_mine:** Small Ray O → Vanadium Queen; 1950-01-01 to 1988-11-27; source msha-controller-operator-history
- **controller_controls_operator:** Small Ray O → Ray Small Mining Company; 1950-01-01 to 1988-11-27; source msha-controller-operator-history
- **controller_controls_mine:** Lammert Tom Et Al → Vanadium Queen; 1979-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Lammert Mining → Vanadium Queen; 1988-11-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lammert Tom Et Al → Lammert Mining; 1988-11-28 to current/open; source msha-controller-operator-history