The longest river on the Iberian Peninsula where Spain is located is the Tajo at 1007 km. However, only 716 km. of the river pass through Spain. The rest passes through Portugal on it's way to the...
The Ebro river is 298 km long.
Check the related link from WikiPedia. Pico Tres Mares, Cantabria, Spain
565 miles
the length of the Ebro river in Spain is 910 km (565 miles)