# Relationship history for MSHA mine 0301749

Current hierarchy: **Monarch Cement Company → Beaver Lake Concrete Inc → BEAVER LAKE CONCRETE INC**

- 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:** Monarch Cement Company → BEAVER LAKE CONCRETE INC; 1990-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Beaver Lake Concrete Inc → BEAVER LAKE CONCRETE INC; 1994-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Monarch Cement Company → Beaver Lake Concrete Inc; 1994-05-01 to current/open; source msha-controller-operator-history