# Relationship history for MSHA mine 3500708

Current hierarchy: **Taiheiyo Cement Corp → Lone Star Northwest → Downtown Plant**

- 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:** Lone Star Industries Inc → Downtown Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Western-Pacific Construction Materials Company → Downtown Plant; 1950-01-01 to 1987-04-08; source msha-controller-operator-history
- **controller_controls_mine:** Riedel International Inc → Downtown Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Riedel International Inc → Western-Pacific Construction Materials Company; 1950-01-01 to 1987-04-08; source msha-controller-operator-history
- **operator_operates_mine:** Lone Star Industries Inc → Downtown Plant; 1987-04-09 to 1988-02-08; source msha-controller-operator-history
- **controller_controls_operator:** Lone Star Industries Inc → Lone Star Industries Inc; 1987-04-09 to 1988-02-08; source msha-controller-operator-history
- **operator_operates_mine:** Lone Star Northwest → Downtown Plant; 1988-02-09 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Taiheiyo Cement Corp → Downtown Plant; 1988-02-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Taiheiyo Cement Corp → Lone Star Northwest; 1988-02-09 to current/open; source msha-controller-operator-history