Nature Communications, Published online: 19 June 2026; doi:10.1038/s41467-026-74382-5 Variations in valley splitting pose a major challenge for coherent electron spin transport in silicon quantum-dot arrays. Here, the authors report spatial mapping of valley splitting in a Si/SiGe shuttle device and demonstrate that selecting shuttling trajectories to avoid regions of low splitting enables micron scale spin transport with preserved coherence.