What is believed to be the oldest river in North America?

Are there any river(s) in North America that run south to north?

The Tennessee River runs both north to south and south to north. (Maybe that's why TN as a state has such an identity crises.) I've been told that this is unique to the Tennessee River, but I have not verified it.

The New River, in Ashe County NC, "is some 300 million years old, the oldest river in America, second in age only to the famed Nile River."

There are several rivers in the US that flow north.

Snake River
St. John's River
Monongahela
Niagara
Wilmette
Shenandoah
Youghiogheny
Cheat
Yellowstone
Big Horn
Cuyahoga
Genessee

and, intrestingly enough, The New River, in North Carolina

There are also several in Canada, and at least two in Mexico.