The river Isar through Munich, Germany, which is one of the larger tributaries of the mighty Danube, is also "unknown". The data outside the USA is definitely l

The river Isar through Munich, Germany, which is one of the larger tributaries of the mighty Danube, is also "unknown". The data outside the USA is definitely lacking in that regard. I guess the names are taken from an underlying hydrologic dataset, and Google (or whoever) maps used purely for visualization.