# Relationship history for MSHA mine 4100081

Current hierarchy: **Heidelberg Materials AG → Heidelberg Materials Southwest LLC → LAKE BRIDGEPORT QUARRY**

- 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:** Lone Star Industries Inc → LAKE BRIDGEPORT QUARRY; 1950-01-01 to 1984-08-19; source msha-controller-operator-history
- **controller_controls_mine:** Lone Star Industries Inc → LAKE BRIDGEPORT QUARRY; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lone Star Industries Inc → Lone Star Industries Inc; 1950-01-01 to 1984-08-19; source msha-controller-operator-history
- **operator_operates_mine:** Pioneer South Central Inc → LAKE BRIDGEPORT QUARRY; 1984-08-20 to 2000-08-03; source msha-controller-operator-history
- **controller_controls_mine:** Pioneer International Ltd → LAKE BRIDGEPORT QUARRY; 1984-08-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pioneer International Ltd → Pioneer South Central Inc; 1984-08-20 to 2000-08-03; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → LAKE BRIDGEPORT QUARRY; 1988-11-14 to 2007-08-22; source msha-controller-operator-history
- **operator_operates_mine:** Hanson Aggregates Central Inc → LAKE BRIDGEPORT QUARRY; 2000-08-04 to 2004-05-09; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → LAKE BRIDGEPORT QUARRY; 2000-08-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Hanson Aggregates Central Inc; 2000-08-04 to 2004-05-09; source msha-controller-operator-history
- **operator_operates_mine:** Hanson Aggregates LLC → LAKE BRIDGEPORT QUARRY; 2004-05-10 to 2020-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Hanson Aggregates LLC; 2004-05-10 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → LAKE BRIDGEPORT QUARRY; 2007-08-23 to 2021-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Hanson Aggregates LLC; 2007-08-23 to 2020-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Heidelberg Materials Southwest LLC → LAKE BRIDGEPORT QUARRY; 2021-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → LAKE BRIDGEPORT QUARRY; 2021-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Heidelberg Materials Southwest LLC; 2021-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → LAKE BRIDGEPORT QUARRY; 2021-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Hanson Aggregates LLC; 2021-10-01 to 2020-12-31; source msha-controller-operator-history