Holy Faith, not Saint Faith.
(I was born in Villa Real de la Santa Fe de San Francisco de Asisi- the Royal City of the Holy Faith of Saint Francis of Assisi, so I know the translation).

More than you want to know-
Rosario, Argentina, was founded at a house which stood at the intersection of the roads to Buenos Aires and Santa Fe (About 1700, when it was called Pago de los Arroyos). It is in the federal province called Santa Fe. Closed to non-Argentine traffic from 1841-1850, it didn't become a port of entry and trade until 1850, and was named a city in 1852 (only about 3000 inhabitants). In the 1870s and later, it was a very important port. Officially it is Ciudad De Rosario.
The River has to be dredged periodically to keep it navigable for modern ships. The passage must have been difficult and subject to change in the days of sail.


The 'Holy Faith' seems to be a poetic addition to the name, never an official designation.