# Relationship history for MSHA mine 1400473

Current hierarchy: **Monarch Cement Company → Kansas Sand & Concrete Inc → Kansas Sand Plant #2**

- 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

- **operator_operates_mine:** Consumers Sand Company Inc → Kansas Sand Plant #2; 1950-01-01 to 1989-04-13; source msha-controller-operator-history
- **controller_controls_mine:** Jackson Albert Jr → Kansas Sand Plant #2; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jackson Albert Jr → Consumers Sand Company Inc; 1950-01-01 to 1989-04-13; source msha-controller-operator-history
- **controller_controls_mine:** Monarch Cement Company → Kansas Sand Plant #2; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Kansas Sand & Concrete Inc → Kansas Sand Plant #2; 1989-04-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Monarch Cement Company → Kansas Sand & Concrete Inc; 1989-04-14 to current/open; source msha-controller-operator-history