A post at the blog The XIVth Century explains it thus.
He searched the area for five months, sailing completely around the Gulf of St. Lawrence, but he found no road to the wealth of the East. When he sailed back to France he took with him Taignoagny and Domagaya, sons of Donnaconna, a Huron Indian chief. They told Francis I a story about a kingdom called Saguenay, a country where yellow metal could be found practically everywhere.Rumors of this city of gold in the forests of the north fueled the fantasies of trappers and explorers for generations, but the reported kingdom was never found. The place name lives on, however.
It was located far up a mighty river which flowed straight down from the north and joined an even greater one where Hochelaga, a city of hundreds of wigwams, stood on an island. The people of this mysterious kingdom, according to the Huron tale, dressed themselves in cloth like that of white men, wore ropes of gold around their necks, and had plenty of precious stones.
Tales of the kingdom of Saguenay continue to exist in my campaign, possibly spurring adventurers to journey to New France, so I'm looking forward to the short film to get a look at the countryside.
On the tangent of movies about New France, I highly recommend Black Robe. Find it if you can.