The Iroquois *are a confederacy of tribes. Not a tribe themselves. Just wanted to clarify that point.
Edit: Wanted to clarify that the Iroquois Confederacy is still alive. Its tribe members consist of the Mohawk, Onondaga, Oneida, Cayuga, Seneca, and Tuscarora people.
You might like /u/Reedstilt's answer about what nations had the best knowledge of the geography of North America.
Edit: And this answer on the first person to cross North America.
(I'm Not an academic, but an Indigenous-issues journalist. But)
In Alan D. McMillan and Eldon Yellowhorn's 2004 book First Peoples of Canada, they note that there have been significant discoveries in the way of southern abalone shells on the shores of the Great Lakes, meaning that the Nations surrounding them (Wendat, Anishinaabe, and Haudenosaunee) were a part of a trade route that descended to the Gulf of Mexico. It stands to reason that trade travelled in all directions, beyond simply north-south, though it was likely hampered by political divisions and war between some Nations. For that reason I presume that the Haudenosaunee Nations would likely know that there were at least peoples to the West, though whether they'd know them by name or custom, I'm not sure. It seems likely they'd know them by reputation based on their most striking features (the way that Inuit often remember the Sivullirmiut/Dorset peoples primarily as very large--and more controversially, as not very smart--as they were generally taller than Inuit but also in conflict with them for land and resources).
There are remarkable trade routes that we know extended throughout North America, bringing Macaw feathers, for instance, up north. We also see a number of mythological similarities between a number of tribes, with figures like the horned/feathered serpant or the spider grandmother reproduced via cultures as far apart as the Cherokee and the Aztecs.
You might find this thread helpful as well: