The calculated distance (air line) between Gasteiz / Vitoria and Zumarraga is approximately 25 miles respectively 39 kilometers.
By car or train, the actual journey to Zumarraga is certainly longer, as only the direct route (as the crow flies) between Gasteiz / Vitoria and Zumarraga has been calculated here.
Air line (approximately)
39 kilometers
21 nautical miles