# Relationship history for MSHA mine 0503553

Current hierarchy: **Zigan Ted → Zigan Sand & Gravel Inc → Zigan Sand And Gravel Pit 2**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Zigan Sand & Gravel Inc → Zigan Sand And Gravel Pit 2; 1981-05-01 to 1992-04-27; source msha-controller-operator-history
- **controller_controls_mine:** Zigan Ted → Zigan Sand And Gravel Pit 2; 1981-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Zigan Ted → Zigan Sand & Gravel Inc; 1981-05-01 to 1992-04-27; source msha-controller-operator-history
- **operator_operates_mine:** Csi Trucking Inc → Zigan Sand And Gravel Pit 2; 1992-04-28 to 1993-05-21; source msha-controller-operator-history
- **controller_controls_mine:** Chaves Steve → Zigan Sand And Gravel Pit 2; 1992-04-28 to 1993-05-21; source msha-controller-operator-history
- **controller_controls_operator:** Chaves Steve → Csi Trucking Inc; 1992-04-28 to 1993-05-21; source msha-controller-operator-history
- **operator_operates_mine:** Zigan Sand & Gravel Inc → Zigan Sand And Gravel Pit 2; 1993-05-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Zigan Ted → Zigan Sand & Gravel Inc; 1993-05-22 to current/open; source msha-controller-operator-history