# Relationship history for MSHA mine 1517923

Current hierarchy: **Heidelberg Materials AG → Heidelberg Materials Midwest Agg, Inc. → AA Limestone**

- 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

- **controller_controls_mine:** Hanson PLC → AA Limestone; 1988-11-14 to 2007-08-22; source msha-controller-operator-history
- **operator_operates_mine:** Aa Limestone Inc → AA Limestone; 1997-04-01 to 1999-03-14; source msha-controller-operator-history
- **controller_controls_mine:** Carolyn K  Spencer → AA Limestone; 1997-04-01 to 1999-03-14; source msha-controller-operator-history
- **controller_controls_operator:** Carolyn K  Spencer → Aa Limestone Inc; 1997-04-01 to 1999-03-14; source msha-controller-operator-history
- **operator_operates_mine:** Aa Limestone-Div/Davon Inc → AA Limestone; 1999-03-15 to 2001-03-30; source msha-controller-operator-history
- **controller_controls_mine:** Davon Inc → AA Limestone; 1999-03-15 to 2001-03-30; source msha-controller-operator-history
- **controller_controls_operator:** Davon Inc → Aa Limestone-Div/Davon Inc; 1999-03-15 to 2001-03-30; source msha-controller-operator-history
- **operator_operates_mine:** Hanson Aggregates Davon, LLC → AA Limestone; 2001-03-31 to 2023-03-15; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → AA Limestone; 2001-03-31 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Hanson Aggregates Davon, LLC; 2001-03-31 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → AA Limestone; 2007-08-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Hanson Aggregates Davon, LLC; 2007-08-23 to 2023-03-15; source msha-controller-operator-history
- **operator_operates_mine:** Heidelberg Materials Midwest Agg, Inc. → AA Limestone; 2023-03-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Heidelberg Materials Midwest Agg, Inc.; 2023-03-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Heidelberg Materials Midwest Agg, Inc.; 2023-03-16 to 2007-08-22; source msha-controller-operator-history