FTP, name this river, which is the second longest in North America and whose drainage basin is the largest of any river in Canada.
It constricts just above Fort Good Hope between some limestone cliffs known as "The Ramparts."  Below Point Separation, it splits into the East, Peel, and Middle Channels, and its large delta is bordered by the Richardson Mountains and the Caribou Hills.  At Fort Simpson it is joined by the Liard River, while near the North Nahanni River it goes past an escarpment of the mountains which share its name.  Its headwaters are the Peace and Athabasca Rivers, while it empties into the Beaufort Sea.  Issuing from the Great Slave Lake, it is named for the white explorer who initially followed its course in 1789.    FTP, name this river, which is the second longest in North America and whose drainage basin is the largest of any river in Canada.
It constricts just above Fort Good Hope between some limestone cliffs known as "The Ramparts."  
the Mackenzie River