Young Earth Creationist, the "Flood," and Fish

[supercorgi]

Isn't there a now freshwater lake, in South America, that contains organisms that usually only occure in salt water?

If memory serves me correctly, the lake is relatively high in elevation, and quite a distance from any ocean...

I am looking for the name & location of it, now.

Are you talking about Lake Titicaca (can't help but snigger at that name)? I don't know if it contains the organisms you're talking about but it's the highest, navigable fresh water lake in the world. It's the largest fresh water lake in South America.