# Relationship history for MSHA mine 3604286

Current hierarchy: **Vetica R C → Vetica Construction Company → VETICA CONSTRUCTION CO. MEDUSA S**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Simpson Silica Sand → VETICA CONSTRUCTION CO. MEDUSA S; 1950-01-01 to 1983-07-06; source msha-controller-operator-history
- **controller_controls_mine:** Allen  Simpson → VETICA CONSTRUCTION CO. MEDUSA S; 1950-01-01 to 1983-07-06; source msha-controller-operator-history
- **controller_controls_operator:** Allen  Simpson → Simpson Silica Sand; 1950-01-01 to 1983-07-06; source msha-controller-operator-history
- **operator_operates_mine:** Vetica Construction Company → VETICA CONSTRUCTION CO. MEDUSA S; 1983-07-07 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Vetica R C → VETICA CONSTRUCTION CO. MEDUSA S; 1983-07-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vetica R C → Vetica Construction Company; 1983-07-07 to current/open; source msha-controller-operator-history