# Relationship history for MSHA mine 4102987

Current hierarchy: **Pioneer International Ltd → Pioneer Concrete Of Texas Inc → Woodlands Plant-03**

- 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 → Woodlands Plant-03; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Pioneer International Ltd → Woodlands Plant-03; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sandco Inc → Woodlands Plant-03; 1980-01-01 to 1981-11-03; source msha-controller-operator-history
- **controller_controls_mine:** Wood Paul A → Woodlands Plant-03; 1980-01-01 to 1981-11-03; source msha-controller-operator-history
- **controller_controls_operator:** Wood Paul A → Sandco Inc; 1980-01-01 to 1981-11-03; source msha-controller-operator-history
- **operator_operates_mine:** Lone Star Industries Inc → Woodlands Plant-03; 1981-11-04 to 1985-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Lone Star Industries Inc → Lone Star Industries Inc; 1981-11-04 to 1985-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Pioneer Concrete Of Texas Inc → Woodlands Plant-03; 1985-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pioneer International Ltd → Pioneer Concrete Of Texas Inc; 1985-04-01 to current/open; source msha-controller-operator-history