# Relationship history for MSHA mine 0201912

Current hierarchy: **Dewit Rudy → Quartzsite Mining Company → Quartzsite Mine**

- 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:** Mitchell Mining Company → Quartzsite Mine; 1979-01-01 to 1980-03-17; source msha-controller-operator-history
- **controller_controls_mine:** Mitchell Frank → Quartzsite Mine; 1979-01-01 to 1980-03-17; source msha-controller-operator-history
- **controller_controls_operator:** Mitchell Frank → Mitchell Mining Company; 1979-01-01 to 1980-03-17; source msha-controller-operator-history
- **operator_operates_mine:** Quartzsite Mining Company → Quartzsite Mine; 1980-03-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dewit Rudy Et Al → Quartzsite Mine; 1980-03-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dewit Rudy Et Al → Quartzsite Mining Company; 1980-03-18 to current/open; source msha-controller-operator-history