# Relationship history for MSHA mine 4202172

Current hierarchy: **Robert  Strang → Strang Excavating, Inc. → Strang Excavating, Inc.**

- 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:** Strang Excavating Inc → Strang Excavating, Inc.; 1997-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Robert  Strang → Strang Excavating, Inc.; 1997-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert  Strang → Strang Excavating Inc; 1997-05-01 to current/open; source msha-controller-operator-history