# Relationship history for MSHA mine 1401142

Current hierarchy: **Richard E  Blake → H B H Rock Company Inc → Truelove 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:** H B H Rock Company Inc → Truelove Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Richard E  Blake et al → Truelove Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Richard E  Blake et al → H B H Rock Company Inc; 1950-01-01 to current/open; source msha-controller-operator-history