# Relationship history for MSHA mine 4100024

Current hierarchy: **Zachry Corporation → Capitol Aggregates Inc → Van Horn Pit & 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Gifford-Hill Cement Company Of Texas → Van Horn Pit & Plant; 1950-01-01 to 1985-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Van Horn Pit & Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Gifford-Hill Cement Company Of Texas; 1950-01-01 to 1985-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Zachry Corporation → Van Horn Pit & Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Capitol Aggregates Inc → Van Horn Pit & Plant; 1986-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Zachry Corporation → Capitol Aggregates Inc; 1986-01-01 to current/open; source msha-controller-operator-history