# Relationship history for MSHA mine 3000975

Current hierarchy: **Heidelberg Materials AG → Hanson Aggregates New York Inc. → Horseheads 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Lycoming Silica Sand Company → Horseheads Plant; 1950-01-01 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_mine:** Koppers Company Inc → Horseheads Plant; 1950-01-01 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_operator:** Koppers Company Inc → Lycoming Silica Sand Company; 1950-01-01 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Horseheads Plant; 1988-11-14 to 2007-08-22; source msha-controller-operator-history
- **operator_operates_mine:** Benchmark New York Inc → Horseheads Plant; 1988-11-14 to 2004-04-06; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Horseheads Plant; 1988-11-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Benchmark New York Inc; 1988-11-14 to 2004-04-06; source msha-controller-operator-history
- **operator_operates_mine:** Hanson Aggregates New York Inc. → Horseheads Plant; 2004-04-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Hanson Aggregates New York Inc.; 2004-04-07 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Horseheads Plant; 2007-08-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Hanson Aggregates New York Inc.; 2007-08-23 to current/open; source msha-controller-operator-history