Robert Cavalier Sieur de la Salle was an explorer and entrepreneur, who sailed up the St. Lawrence River to the Great Lakes. He also managed to negotiate the portage (a means of travel mostly by water, but carrying the boats and goods around water falls and between navigable waterways) between the Lakes and the Ohio River. He did explore the Mississippi, as the previous poster mentioned. LaSalle had a theory that there was a river flowing in a southwesterly direction that emptied into the Vermillion Sea. This was a mythical body of water, that could have been the Gulf of California, but it supposedly emptied into the Pacific Ocean, thus giving access to China (la Chine in French) via the St. Lawrence, then under French control. Some of his men, reportedly thought this whole theory was foolish, and named some rapids in the St. Lawrence “La Chine”, as a joke.

The theory about the Vermillion sea is a curious one. I’ve wondered if they could have heard of it from the Spanish, who had explored the area around the gulf of California, and would certainly have noticed the mouth of the Colorado River, which, in pre-Hoover dam days, emptied into the gulf. Thinking, there’s a big river, emptying into a gulf that emptied into the Pacific, perhaps its a Northwest Passage.

He built a vessel for use on the Lakes called the Griffon.

There is a very interesting book on the life of La Salle… your local library should have it. La Salle discovered the Mississippi river among other things