# Relationship history for MSHA mine 2300134

Current hierarchy: **Buzzi S p A → Buzzi Unicem USA → Lone Star Quarry & Mill**

- 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:** Marquette Cement Manufacturing Company → Lone Star Quarry & Mill; 1950-01-01 to 1982-04-14; source msha-controller-operator-history
- **controller_controls_mine:** Gulf + Western Industries Inc → Lone Star Quarry & Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gulf + Western Industries Inc → Marquette Cement Manufacturing Company; 1950-01-01 to 1982-04-14; source msha-controller-operator-history
- **controller_controls_mine:** Lone Star Industries Inc → Lone Star Quarry & Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Lone Star Industries Inc → Lone Star Quarry & Mill; 1982-04-15 to 1999-10-03; source msha-controller-operator-history
- **controller_controls_operator:** Lone Star Industries Inc → Lone Star Industries Inc; 1982-04-15 to 1999-10-03; source msha-controller-operator-history
- **operator_operates_mine:** Buzzi Unicem USA → Lone Star Quarry & Mill; 1999-10-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dyckerhoff AG → Lone Star Quarry & Mill; 1999-10-04 to 2003-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Dyckerhoff AG → Buzzi Unicem USA; 1999-10-04 to 2003-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Buzzi S p A → Lone Star Quarry & Mill; 2004-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Buzzi S p A → Buzzi Unicem USA; 2004-01-01 to current/open; source msha-controller-operator-history