# Relationship history for MSHA mine 4104107

Current hierarchy: **Zachry Corporation → Zachry Construction Corp → ZACHRY CONSTRUCTION CORP.**

- 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:** Zachry Construction Corp → ZACHRY CONSTRUCTION CORP.; 1999-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Zachry Corporation → ZACHRY CONSTRUCTION CORP.; 1999-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Zachry Corporation → Zachry Construction Corp; 1999-10-01 to current/open; source msha-controller-operator-history