# Relationship history for MSHA mine 2103424

Current hierarchy: **David A  Sundblad; John W  Sundblad → Sundblad Construction, Inc. → Cedar Rapids Portable**

- 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:** Sundblad Construction, Inc. → Cedar Rapids Portable; 2004-05-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** David A  Sundblad et al → Cedar Rapids Portable; 2004-05-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David A  Sundblad et al → Sundblad Construction, Inc.; 2004-05-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John W  Sundblad et al → Sundblad Construction, Inc.; 2004-05-17 to current/open; source msha-controller-operator-history