# Relationship history for MSHA mine 0504423

Current hierarchy: **Continental Materials Corp → Castle Concrete Company → CONTINENTAL PIT**

- 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

- **controller_controls_mine:** Continental Materials Corp → CONTINENTAL PIT; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Castle Concrete Company → CONTINENTAL PIT; 1989-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Continental Materials Corp → Castle Concrete Company; 1989-11-01 to current/open; source msha-controller-operator-history