# Relationship history for MSHA mine 0400278

Current hierarchy: **E O  De Silva → Oliver De Silva Inc → Cordelia Quarry**

- 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:** Oliver De Silva Inc → Cordelia Quarry; 1950-01-01 to 1979-08-08; source msha-controller-operator-history
- **controller_controls_mine:** E O  De Silva → Cordelia Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** E O  De Silva → Oliver De Silva Inc; 1950-01-01 to 1979-08-08; source msha-controller-operator-history
- **operator_operates_mine:** Delta Pacific Materials → Cordelia Quarry; 1979-08-09 to 1980-07-16; source msha-controller-operator-history
- **controller_controls_mine:** Delta Pacific Materials → Cordelia Quarry; 1979-08-09 to 1980-07-16; source msha-controller-operator-history
- **controller_controls_operator:** Delta Pacific Materials → Delta Pacific Materials; 1979-08-09 to 1980-07-16; source msha-controller-operator-history
- **operator_operates_mine:** Oliver De Silva Inc → Cordelia Quarry; 1980-07-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** E O  De Silva → Oliver De Silva Inc; 1980-07-17 to current/open; source msha-controller-operator-history