[01-7700]

True. Bonus fact: The Niagara River is actually a straight not a river. Its is a body of water that connects two larger bodies of water. Let me know if you end up in the area.

isn't it more than one river/straight? one above and one below ground

 

[Tinsnips]

isn't it more than one river/straight? one above and one below ground

I don’t think so. There are huge tunnels underground for the power plants down stream but the don’t go from lake to lake.