The outlet of Big Moose Lake forms the North Branch in northern Herkimer County.

Owing to its high gradient as it drops out of the mountains, The Moose is a favorite destination for whitewater rafters, kayakers and canoeists.

The Middle Moose is a Class II-III section of river from the gaging station in McKeever to Rock Island.

The Lower is a Class III-V section from Rock Island to just above Fowlerville Falls, which is run commercially in early spring and includes drops such as Tannery, Froth Hole, Mixmaster and Miller's Falls.

In the Spring and Fall of each year, hundreds of whitewater paddlers descend on the Moose from all parts of the US and eastern Canada.