# Relationship history for MSHA mine 4502865

Current hierarchy: **Harbor Rock Inc → Harbor Rock Inc → Camp 19 Mile 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Harbor Rock Inc → Camp 19 Mile Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Harbor Rock Inc → Camp 19 Mile Pit; 1980-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harbor Rock Inc → Harbor Rock Inc; 1980-09-01 to current/open; source msha-controller-operator-history