The calculated distance (air line) between Unión Chocó and Alcalde Díaz is approximately 156 miles respectively 250 kilometers.
By car or train, the actual journey to Alcalde Díaz is certainly longer, as only the direct route (as the crow flies) between Unión Chocó and Alcalde Díaz has been calculated here.
Air line (approximately)
250 kilometers
135 nautical miles