# Relationship history for MSHA mine 3603227

Current hierarchy: **Medusa Corp → Medusa Aggregates Company → Medusa Aggregates Company - Edinburg**

- 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

- **controller_controls_mine:** Medusa Corp → Medusa Aggregates Company - Edinburg; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Vanport Sand & Gravel Inc → Medusa Aggregates Company - Edinburg; 1950-01-01 to 1984-06-05; source msha-controller-operator-history
- **controller_controls_mine:** Vanport Stone Inc → Medusa Aggregates Company - Edinburg; 1950-01-01 to 1984-06-05; source msha-controller-operator-history
- **controller_controls_operator:** Vanport Stone Inc → Vanport Sand & Gravel Inc; 1950-01-01 to 1984-06-05; source msha-controller-operator-history
- **operator_operates_mine:** Kenlar Construction Supply Company Inc → Medusa Aggregates Company - Edinburg; 1984-06-06 to 1987-06-18; source msha-controller-operator-history
- **controller_controls_mine:** Kenlar Construction Supply Company Inc → Medusa Aggregates Company - Edinburg; 1984-06-06 to 1987-06-18; source msha-controller-operator-history
- **controller_controls_operator:** Kenlar Construction Supply Company Inc → Kenlar Construction Supply Company Inc; 1984-06-06 to 1987-06-18; source msha-controller-operator-history
- **operator_operates_mine:** C & C Vanport Sand & Gravel Plant #3 Inc → Medusa Aggregates Company - Edinburg; 1987-06-19 to 1990-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Victor  Mashuda → Medusa Aggregates Company - Edinburg; 1987-06-19 to 1990-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Victor  Mashuda → C & C Vanport Sand & Gravel Plant #3 Inc; 1987-06-19 to 1990-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Medusa Aggregates Company → Medusa Aggregates Company - Edinburg; 1990-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Medusa Corp → Medusa Aggregates Company; 1990-06-01 to current/open; source msha-controller-operator-history